OzVMX Forum
Clubroom => Tech Talk => Topic started by: firko on August 01, 2011, 12:29:25 pm
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Many of you will remember Yamaico's step by step build build up of his 465 Yamaha dirt tracker a couple of years ago. http://ozvmx.com/community/index.php?topic=9177.0 (http://ozvmx.com/community/index.php?topic=9177.0)
Well, Pete's back at it again and has decided to build a bike that's not intended to be a class perfect racer but be "just something to hack around on" at Classic Dirt, HBBB and that sort of event.
The object is to build a well behaved motocross oriented bike out of left over, donated and bargain basement junk parts. The budget is to be a nice round $1000. Peter is a very handy tradesman and is capable of doing his own welding, machining and engine building. He is even doing his own soda blasting and powder coating using equipment he's built himself. Of course most of us don't posess such a well equipped workshop but this exercise will hopefully show what can be done with a bit of lateral thinking, a reasonable amount of basic workshop skill and little overall outlay. If you haven't got a powder coater under the bench, don't worry too much, rattle cans do a pretty good job and paying for blasting wouldn't dent your budget too much.
Building bikes like this allows us to use a bit of hot rod injenuity and 'suck it and see' experimentation. If it doesn't work or looks wrong, pull it apart and try something else. Once you get rolling on these projects they become a lot of fun and the finished product is something unlike anything else in the pits. Follow this and see how a pile of shit can evolve into a unique bike.
The parts list starts with a KLX250 rolling chassis ($200), DT400 engine ($100, courtesy of Vandy), DT250 frame ($0, courtesy of Nathan S) and YZD guards and YZ125C tank (courtesy of Peters cousin Scott from VMX Plastics). Pete plans on fitting the forks, rear frame, swing arm and shocks from the KLX onto the DT frame in his usual Illawara Dr Frankenstein manner. Nobody builds a better Frankenbike special than Pete.
The DT400 engine came with a YZ gearset and head so with a bit of porting, a 38mm Mikuni, YZ250 ignition, a decent pipe and some head reworking should see more than enough horsepower for some serious fun.
Here's the "Starter Pak" lined up ready to undergo surgery.
(http://img.villagephotos.com/p/2005-8/1062154/pete%201.JPG)
Pt 1 in Pete's words
"I started on the bike last night. Cut the old steering stop off the DT frame and fitted the steering stop from the KLX. Machined a sleeve for the KLX bottom yoke so I could use the DT steering head bearings. The front end all fitted up good so then I drilled out the spotwelds on the tank mounts and repositioned them for the YZ tank. The tank fits up good with enough clearance on each lock, but still have to cut the bottom out of it and beat out all those ball dents in the top. Tonight I’ll make the new front engine mounts as the DT250 and DT400 are different in the front. The two back mounts are correct, which makes it really easy to do the front ones. Once that is finished the next job will be to shorten the swing arm. The DT frame is a lot longer in the main frame than the KLX, so the standard length swingarm bolted into the standard position on the DT frame makes the thing look like a hillclimber. I can get about 50mm out of the swingarm quite easily, but I’ll have to reposition the upper shock mounts accordingly when I weld the rear frame loop from the KLX onto the DT frame. This could prove to be famous last words, but nothing appears like it is going to be too difficult with the whole project. I’ve done a budget estimate, and $1000 looks quite achievable."
(http://img.villagephotos.com/p/2005-8/1062154/pete%202.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%205.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%207.JPG)
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i bet Nathans jealous already looking at that frame :D
that'll be one cool bike when it's all done Pete 8)
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Tacked the rear subframe in place last night and machine some sleeves to mount the rear guard. Have to finish the rear tank mount next and then finish welding out the frame. Getting close to a rolling chassis now. Looks OK I think, and measures up pretty much the same as the KLX with regards to wheelbase, rake, seat height etc. I would think that the DT motor would be a bit lighter than the KLX motor, so it should work OK. Still got all the fiddly bits to do – brake pedal, torque arm, chain rollers and wear pads.
(http://img.villagephotos.com/p/2005-8/1062154/pete%204.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%206.JPG)
Got the front engine mounts fabricated and installed. Shortened the swingarm by about 40mm and welded the new tube in. Made swingarm bushes out of nyloil, which is self lubricating nylon and was only $25 for a 40x300 bar. Really easy to machine and should last longer than the needle rollers that were in there. Welded a lug on the bottom triple tree (spare one from you) so I can bolt the YZ guards up to it. I then powder coated both the top and bottom trees, ready for installation. The next thing to do is mount up the swingarm and shocks so that I can weld the rear frame on and make the rear tank mount. All going pretty well so far.
(http://img.villagephotos.com/p/2005-8/1062154/pete%203.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%208.JPG)
Repaired the crank on the weekend. It was rusted really badly and after I blasted it I noticed the timing side seal surface was heavily pitted. I could buy a good second hand crank off ebay but I’m trying to stick to the budget so I machined down the seal surface 1.5mm and then made a sleeve out of an old gearshaft and shrunk it on, then machined it back to size. I also took a clean-up cut off the outside of the wheels – only a couple of thou so it shouldn’t affect anything. Put the wheels back together and trued them ready for motor assembly.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2011.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2010.JPG)
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Wow, if Yamaico Pete was a lady, I'd marry him.
I just love the step by step progress from someone who knows what he's doing around a workshop
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I Lowered the swinging arm pivot by 13mm last night, which took hours to do, but it was worth the sffort as the chain line looks and works a lot better. Also made the rear tank mount, lengthened the rear torque arm and finished welding out the frame where the rear loop joins. Have to do some mods to the seat as it conflicts with the rear tank mount, and then send it out for covering. I’d like to get an industrial sewing machine and have a go at making seat covers but dirt track legend Doug Platts does my seats and he’s an awesome trimmer. I mocked the bike up and am still undecided about having the tank polished aluminium or painting it to match the guards.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2013.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2012.JPG)
The bike is starting to come together and looks pretty purposeful. I think the tank should be yellow (mf).
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Firko
Will you make one of your custom aluminum air boxes.
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Mick.....have a proper re read, I'm not building this bike, it's Yamaico Petes project, I'm merely the presenter.
Creepy that you mention it though, just this morning I made a cardboard mock up for an alloy airbox for my Hindall.
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I'm watching with interest as I'm sure many others are. Fantastic to see a master at work undertaking what for me would be very tricky jobs.
These are always my favourite threads ... keep the photos coming 8) 8)
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A good pipe and carb setup ( a nice 38 bing) and a few port tweeks this thing would be more than interesting.
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This is a great thread! I'm looking forward to seeing the finished product.
It's great to see what people with some talent and good ideas can do, and all for under $1000, brilliant!
Tex
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I'll be checkin' in regularly to follow the progress… so keep on top of the build Firko!!!
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(http://img.villagephotos.com/p/2005-8/1062154/pete%2012.JPG)
I'm guessing here but I take it that it is the DT front loop with the KLX rear loop (from the swing arm pivot to rear of tank), welded on, (giving the KLX seat base and shock mounts already pre-positioned). And the KLX swing arm mount adapted for the DT frame.
Nice, neat, tidy, relatively easy and looks 'factory' ;) 8).
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I'm guessing here
It's all explained in the text
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Firko tell pete i feel a yellow 125 tanked blender coming on!!!
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am still undecided about having the tank polished aluminium or painting it to match the guards.[/b]
i like a lot of Yamaha paint jobs but must admit to not being too much of a fan of the polished tank look, except on some of the Brit bikes.
i wonder what a black tank/yellow stripe would look like as opposed to the yellow tank/black stripe ;D
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I reckon it looks about 'right'.
With 400 instead of 125 it would have that factory look that should confound the pundits and cause a few WTF's(http://i323.photobucket.com/albums/nn458/mx250syd/icons/smiley79.gif)
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am still undecided about having the tank polished aluminium or painting it to match the guards.[/b]
i like a lot of Yamaha paint jobs but must admit to not being too much of a fan of the polished tank look, except on some of the Brit bikes.
i wonder what a black tank/yellow stripe would look like as opposed to the yellow tank/black stripe ;D
I've been thinking about a TT500 style combination for my 250 C. Paint the main bit of the tank and polish the bit inside the decal. The best of both worlds ::)
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Not much to report on today as I’m waiting on the cylinder to get here from the US so I can build the pipe. Once the pipe is made I can pull the bike apart and paint the frame and build the wheels and engine. Still got the bike mocked up so I can make sure the pipe clears the front guard and tucks in beside the back guard. I did manage to fabricate the sidecover brackets and weld them in place, the chain runner on the swingarm made and installed (milled down some 15mm nylon with the router and the bent it with the heat gun – terrible colour, but you’ve got to take what you can get), notched the bottom of the seat to clear the rear tank mount and machined up a sleeve to replace the speedo drive on the front wheel (see photos). If the cylinder doesn’t get here today I can make the muffler for a start. I also have to move the fuel tap mount to the other side of the tank as the pipe will foul it in the original position.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2014.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2015.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2016.JPG)
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tell you what it reminds me off, that Rc 125 that Jonnyos selling. What barrell are you waiting on ?
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I'll get in on the action here....I will donate a brand spanking new machined billet feul tap spigot if you like to weld on the tank.....send me your details if you want one....keep up the good work.
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the bikes just taken on a real Aussie theme now Pete with that green chain guide.
Green & Gold ;D
I'll get in on the action here....I will donate a brand spanking new machined billet feul tap spigot if you like to weld on the tank.....
it'd be quicker if he machined his own Davey ;)
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I have some GC Yamaha yellow fork boots in 38mm if you want them.
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tell you what it reminds me off, that Rc 125 that Jonnyos selling.
Barbarian .....
Friend of mine did RM250c powered KLX back in the day that went like a shower of shit. But like the whole KLX/DT400 concept, one of the best handling twin shock chassis combined with.... an engine
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Nah yellow gaiters 'id be too much IMO
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I'll get in on the action here....I will donate a brand spanking new machined billet feul tap spigot if you like to weld on the tank.....send me your details if you want one....keep up the good work.
Hi Davey,
Thanks for the kind offer but I'm using a YZ465 tap out of the junk stash, so I have to make up a mounting plate and weld it in,
Pete.
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I have some GC Yamaha yellow fork boots in 38mm if you want them.
Geez, another kind offer, but the forks are only 36mm. The gaiters are stuffed so I'll probably just go with the bare look,
Thanks anyway,
Pete.
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Pete, you've got to stop all this new age motorcycle building.
You're making the rest of us look bad.
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This is probably a really silly question Pete ....
Was there a reason you opted for using the DT frame with KLX dangly bits, as opposed to using the KLX roller with the DT motor.
I would have thought that a superb handling bike (KLX) with an engine such as yours would be perfect.
Did you have any luck with sorting the rear shoes ?
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This is probably a really silly question Pete ....
Was there a reason you opted for using the DT frame with KLX dangly bits, as opposed to using the KLX roller with the DT motor.
I'll let Pete answer that but I'm prtetty sure the answer is "because I can" or "the bits were there" 8) ;D.
I would have thought that a superb handling bike (KLX) with an engine such as yours would be perfect.
An interesting question Grouty 8). I was thinking of the same thing but thinking of it in reverse - would the LTR and LT/front improve or change the basic characteristics of the centre loop?
The DT frame is essential the MX250/360/SC500 frame in every regard (AFAIK - with a few extra brackets welded on). I don't think it is a hopeless MX frame when it comes to strength and integrity. The geometry might be a little questioned for MX (The MX/DT was intended more for high speed (Play racing, Socal desert, trail and street) rather than cutting a line inside a Maico). The 'so so' cheap mass production suspension would only exasperate any geometry limitations. I believe the MX chassis can be improved by improving the suspension, quicken the steering by reducing the trail and lengthening the swingarm (25mm). The dangling bits that Pete is adding will address all of these issues - for better or worst remains to be seen.
I would also question the assumption that the KLX is a great handling frame - I think it was a very 'untaxed' frame with the puny KL250 20hp trying to pull it out of shape and propel it forward ::) :-[. A tuned DT400 will be a very different proposition to the KL250 motor.
Besides, I think this approach is new and will give a very 'factory' appearance that will confound the pundits ;D.
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This is probably a really silly question Pete ....
Was there a reason you opted for using the DT frame with KLX dangly bits, as opposed to using the KLX roller with the DT motor.
I would have thought that a superb handling bike (KLX) with an engine such as yours would be perfect.
Did you have any luck with sorting the rear shoes ?
Hi Ian,
I had to use the DT loop because the DT motor is centre exhaust port and the single downtube KLX frame won't work. I opted for the DT motor because it was cheap and they're are very tunable. I've always been primarily a Yamaha guy, and I wanted to use a YZ400 motor but Vandy offered me a DT400 with YZ gearset for $100. Unfortunately the motor had been sitting in water for some time before Vandy got it and the bore was on last over and heavily rusted. I managed to find a complete top end from a YZ400 on Mark's swapmeet for $75 so I'm going to have pretty close to a YZ400 when I'm finished.
As Graeme says, I'm really not too sure if this will work but what the heck, it's not a very expensive experiment. If it doesn't work I'll still have a good almost YZ400 motor and some rebuilt KLX wheels and suspension.
Thanks for the help with the brake shoes - I got some EBC DT ones ready to go in once I've repaired the rear hub,
Pete.
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I Didn’t do much on the project last weekend as I’m still waiting on the cylinder to get here so I can make the pipe. I did start making some of the cones but I can’t do much more than that. I soda blasted the tank and welded in the fitting for the YZ465 fuel tap on the opposite side. I had to cut a hole in the bottom of the tank for the fitting and was able to get a brass drift in there and knock a couple of the dents out of the top. Should only need a light wipe of bog to get it straight now. Also made up a new rear brake rod and lengthened the rear brake arm. The foot brake pivot is sloppy in the frame so when I pull it all apart again I’ll have to bore that out and make a bush for it.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2017.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2018.JPG)
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Still waiting on the cylinder so last night I repaired the rear hub. The wheel bearings were shot and the backing plate wore away the lip on the hub. Built it back up with the tig and machined it back to size. The brake drum was pretty badly scored so I cleaned it up as well. DT175 brake shoes are a perfect fit for the slightly oversize drum (thanks to info from Grouty), so the brake should be good now. Almost running out of things to do until I get the pipe finished so I made some front number plate mounting clamps. Hopefully the cylinder will get here soon and I can get moving on things again,
(http://img.villagephotos.com/p/2005-8/1062154/pete%2021.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2020.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2019.JPG)
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Great stuff. Can't wait for the next update.
All this and Doc is back as well. Good Times!!
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Still waiting on the elusive cylinder so I started on the wheels. The rims had a few gouges in them so I tigged them up and then sprayed them with oven cleaner to remove the anodising and then buffed them. There's still a few marks in them but they don't look too bad. Bead blasted the hubs and painted them satin black. Zinc plated all the spokes so when the paint hardens up I can put the wheels together. The Jane zinc kit does a great job and the best part is you can do the parts as you need them and don't have to worry about losing anything at the platers. I haven't used the kit for a couple of years so I got some new electrolyte from Janes but I tried the old stuff first. Just strained it, added a bit of brightener and it still worked perfectly. Monday I'll put the wheels together and hopefully have a cylinder so I can finish the pipe and make the airbox. Once that's done I can pull it all apart and paint the frame and tank and start assembling it.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2024.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2023.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2022.jpg)
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Still waiting on the elusive cylinder so I started on the wheels. The rims had a few gouges in them so I tigged them up and then sprayed them with oven cleaner to remove the anodising and then buffed them. There's still a few marks in them but they don't look too bad.
I am curious on the oven cleaner thing because i have tried it before and it did nothing to the annodizing at all. What brand did you use and how long do you leave it soaking on the rims?
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Turn it up Pete :) .... you have done more in 7 days of which would take me near on 7 month.
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Firko how long did it take you to zinc plate all of the spokes in that photo.
Zane
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Still waiting on the elusive cylinder so I started on the wheels. The rims had a few gouges in them so I tigged them up and then sprayed them with oven cleaner to remove the anodising and then buffed them. There's still a few marks in them but they don't look too bad.
I am curious on the oven cleaner thing because i have tried it before and it did nothing to the annodizing at all. What brand did you use and how long do you leave it soaking on the rims?
I used Ezy-off Oven Cleaner in the red can with yellow writing (heavy duty). It's the high strength stuff and I did them twice and left it on for about 20 minutes each time. The rim turns black but you just rub it off with a scotchbrite and then start buffing.
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Firko how long did it take you to zinc plate all of the spokes in that photo.
Zane
15 minutes at 1.5A for 6 at a time. Really doesn't take too long.
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I am curious on the oven cleaner thing because i have tried it before and it did nothing to the annodizing at all. What brand did you use and how long do you leave it soaking on the rims?
Pete's oven cleaner de-anodize thick works, I've tried it and it works a treat. Another thing that I found works is garage floor cleaner that contains an acid but I can't quite remember which one.
Firko how long did it take you to zinc plate all of the spokes in that photo.
What Yamaico Pete said....Zane, this isn'y my project, it's all Yamaico's work, all I'm doing is to upload the sequence. Read the text and the whole story unfolds before your eyes ;).
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Not much to report on the bike as I had a few non bike projects over the weekend. I did manage to get the wheels built on Sunday night, which took a while as the Swedish speedway Grand Prix and the Moto GP were both televised. I found a soft terrain front that I had from the old thumper nats days and a reasonably good rear that was in my tyre rack. Last night I did some more zinc plating, which is good fun and very stress-free. I have to make new plates for the chain guide tonight as the old ones aren’t long enough, and I might start on the airbox as I pretty much know where the pipe is going to run, within ½’ or so. I need to clean the crankcases up and paint them ready to put the motor together. Hopefully the cylinder will turn up soon….
(http://img.villagephotos.com/p/2005-8/1062154/pete%2026.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2025.jpg)
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I`am enjoying this, Yamaico you can come and spend some time in my shed while your waiting for your barrel
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I`am enjoying this, Yamaico you can come and spend some time in my shed while your waiting for your barrel
You've got a couple of CR's Snowy - don't think I can help you there ;D
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pete/firko
can you tell me what the front wheel is and brake plate
cheers
jim
ps its looking good did you get the softwere sorted out
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Jim ....... it's KLX250 / KDX175 (and probably a KX125 A .. summat).
It's looking really good Pete. Keep up the work. If you didn't sit on your bum watching the Moto GP you would have had loads more done. Good race though.
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pete/firko
can you tell me what the front wheel is and brake plate
cheers
jim
ps its looking good did you get the softwere sorted out
Software is all sorted, thanks Jim.
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Pete just had a good bit of luck with finding a 'special' YZ400F engine..I'll let him explain.........
Just talked to a mate who’s CR250 engine I’m rebuilding and he casually mentioned that he has a complete YZ400F motor in his garage that I can have. The motor actually came out of a bike that I rode in the Nepean 6 hour in 1981. I was riding and we were in second place on the same lap and closing rapidly on the leaders with 15 minutes to go when the piston seized, which I believe was a result of the pit crew forgetting the oil in the fuel for the last pit stop. Anyway, he ended up with the bike and took the engine out for some reason and the rolling chassis got knocked off from his garage, so the engine has been sitting under his bench for the last 30 odd years. I’m gobsmacked that I will end up with it. Wish he had told me this a month ago before I started on the CD project bike. Looks like another el-cheapo will be in the makings. Might stick it in a ???? frame and make a serious racer out of it. Oh, the mind boggles…
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Come on Firko you know its going in a Hindle frame
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Bazza....It's not my project :'( and as much as I like Pete, he's not getting one of my precious Hindalls (yet). Moving on....
Well, my cylinder is still in LA somewhere, so I’m hoping it’s not lost. Almost running out of things to do so I made the new chain guide side plates and the muffler housing and end cap. I don’t have a magneto cover so I might make one of them next. I mounted some oval number plates for the side numbers but they look a bit “add-on” so I’ll probably think about making some sidecovers as well. I’m going to leave the airbox until the pipe is finished, so there’s really not a lot left.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2028.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2027.JPG)
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Pete,
I reckon there's a Maico frame (AW?) just begging to be a new home for the YZ400F engine.
A pre78 Yamaico would be nice company for yr pre75 one.
(Edit: or would it need to be a Magnum frame to be correct era for the 400F engine??)
Lovely work on this project too. Wish I had quarter of yr talent!
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I reckon there's a Maico frame (AW?) just begging to be a new home for the YZ400F engine.
An updated version of Pete's original Yamaico. I love it! (apologies for the crap scan and photo, it's the only one I've got)
(http://img.villagephotos.com/p/2005-8/1062154/Yamaico.jpeg)
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Pete,
I reckon there's a Maico frame (AW?) just begging to be a new home for the YZ400F engine.
A pre78 Yamaico would be nice company for yr pre75 one.
Lovely work on this project too. Wish I had quarter of yr talent!
You're right John, an AW would be perfect. I'll have to start scouring Mark's swapmeet for a rolling chassis.
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I couldn’t do much on the bike on the weekend so I soda blasted the cases, and they’re now ready for painting. I was at a good mate of mine’s place on Sunday that used to own a bike shop and he donated a set of fork seals. He had a box full of different sizes that have been sitting on a shelf for years, which I’ll keep in mind for the next project. My cylinder turned up yesterday and it’s in great shape. I bought it from Mike Bolde from Mark’s Swapmeet, who is a really good guy to deal with. It was just as he said it was and he even painted the head and cylinder. The piston has very little wear and the bore is good but it could probably do with a set of rings, which he told me. Last night I made a rough mock-up of the exhaust out of cardboard to check the fit and it looks OK so tonight I’ll be developing and cutting out a whole bunch of little and big cones, ready to weld together. I’m at around the $850 mark at the moment but I still have to get some muffler packing, the seat covered and whatever else so I’m probably going to be a little over the $1000.
I have to go back to Indonesia at the end of the month for 3 or 4 weeks so I want to get as much done as possible between now and then. I’d really like to get the pipe and airbox finished and the tank and frame painted before then so I only have to do the final polishing, powdercoating and assembly when I come back.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2029.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2030.JPG)
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Looking good Yamaico.
What size compressor do you use for soda blasting? I've done some very small pieces using one of those cheap 2HP (122L/min) compressors but its bloody noisy and barely keeps up. Thinking about upgrading without going overboard.
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Looking good Yamaico.
What size compressor do you use for soda blasting? I've done some very small pieces using one of those cheap 2HP (122L/min) compressors but its bloody noisy and barely keeps up. Thinking about upgrading without going overboard.
I've got a 13cfm compressor and it struggles a bit. That's the only problem with the soda blaster - air consumption. I have found that it works well on 70 psi, which makes it a bit easier. It's a handy thing though, as it doesn't damage seals, rubbers, plastic etc. and is really good on things like carbie bodies.
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If you're struggling at 13cfm then mine is way off at only about half that. Might just get another cheapy and connect both together in parallel when blasting.
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I took advantage of the sun yesterday afternoon and painted the cases, so as soon as I get the seals and gaskets I can put the motor together. I found an old set of cases in the stash that I am using for the mock-up, so the good ones don’t have to go in until last. Started making the header pipe last night and noticed the exhaust flange was only 42mm, with the exhaust port being 45mm, so I had to remake the flange first. Finished that and then made some of the header pipe and hope to finish it tonight. I have never made an up-pipe before, they are really fiddly and take ages. Took about 4 hours to make nine little cones and weld them together. Once I get the header going in the up direction the pipe only needs one more major change of direction at the head and then it’s just minor fit up from there. I have to cross over to the other side of the bike so I need to keep an eye on the carbie top to make sure I have enough room for the throttle cable to clear the pipe.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2032.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2031.JPG)
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Got most of the pipe finished yesterday, just the baffle cone and stinger to weld on, and a couple of mounting brackets. Tucking it in under that skinny little YZ tank was testing, but it's pretty much out of the way of the left knee, and clears the plug cap and throttle cable, so it should be OK. Stripped the forks in between welding the pipe and bead blasted the legs, replaced the seals and put them back together. I was going to polish them but they looked good after I blasted them, so I left them that way.
By the way, if anyone wants an up-pipe built just give me a call - and I'll give you Geoff Morris's phone number. That wasn't a lot of fun at all.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2033.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2034.JPG)
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That pipe looks mighty short, I hope you didn't use any free online pipe design calculators? Nice work on it just the same.
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Thanks Lozza. The pipe is actually fairly long, but I went down a fair way and back up with the header to use up a bit of length so the pipe didn't stick out the back too far. I certainly don't use any of that free software (did a check against one of my pipes once and it was nowhere near it and about 150mm dia. in the belly!!), I'm a bit old school and still use Bell's book. My brother John is a real whiz with that and he usually designs my pipes (he built a '73 CR250 roadracer years ago and it was a rocketship). The 465 flat track bike's pipe were dimensions that Geoff Morris was kind enough to give to me and after checking they were very close to what would be generated from Bell's formulae, and it's no slouch. I had a guy give me a "super very fat design" for my Yamaico once and it was significantly slower than the Bell pipe that John designed,
Cheers,
Pete.
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tripleclamps Pete,
how'd you go fitting the KLX clamps into the Yamaha frame?
i've just fitted the same and after solving the bottom bearing dilema with a hardened sleel sleeve i now only have a very small amount of thread sticking through the top bearing for the locking nut.
i figure once the forks are all bolted up it should be ok but am just curious as to how much thread you have sticking out of the top bearing for the locknut
cool work too mate 8)
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I just made the same sleeve Vandy, but I machined a recess into the bottom of it that fitted over the spigot on the bottom tree and gained a bit more length that way. I have almost a full adjusting nut of thread which is plenty. Be happy to make you a sleeve if you need another one,
Pete.
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looking good pete,I feel a yamaico blender coming on
Kiwi klub Kevlar
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Already got it planned Mike ;D
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Finished the pipe and muffler mounts last night. Need to find some perforated steel so I can roll up the muffler tube then that’s all finished. All that’s left is the airbox and when that’s done the bike can be stripped, painted, and assembled. Still have some more zinc plating and powdercoating to do which can be finished between painting.
We’ll soon know whether it’s a winner or a binner ;D.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2035.JPG)
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Need some perf tube--try an exhaust shop, you can get it in aluminised or stainless in most sizes from their suppliers-or you can dig in their bin and cut up an old muffler, you will find some in most muffler types.
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Great idea, thanks. I'll hit the muffler shop tomorrow.
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You can also get perforated tubing from any MCS dealers
http://www.mcsonline.com.au/index.php?option=com_virtuemart&page=shop.browse&category_id=213&Itemid=126
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Jeez, give the exhaust shop a break-prob haven't seen a customer for a week by now.....
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Finished the muffler. Got some perforated sheet from the muffler shop, powdercoated the encaps, and installed the muffler packing. Made the airbox and an adaptor plate so I could use an old 465 airbox rubber that I found in the stash. Just have to drill the front of the airbox and then make the mounting brackets and it's ready to paint. Once that's done I can pull it all apart and paint the frame.
(http://img.villagephotos.com/p/2005-8/1062154/pete%2036%20.JPG)
(http://img.villagephotos.com/p/2005-8/1062154/pete%2037.JPG)
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INTERVAL:
For those following Pete's latest online creation there will be a small break in the program while he spends a month or so in Indonesia in the course of his work as a engineer. He's missing his baby already so you can bet he'll be straight into it once he's sorted out the Indonesian dilemna ;D.
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INTERVAL:
For those following Pete's latest online creation there will be a small break in the program while he spends a month or so in Indonesia in the course of his work as a engineer. He's missing his baby already so you can bet he'll be straight into it once he's sorted out the Indonesian dilemna ;D.
Pretty piss weak if you ask me. Is this any way to show his commitment to this project. >:(
I expected better!!
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INTERVAL:
For those following Pete's latest online creation there will be a small break in the program while he spends a month or so in Indonesia in the course of his work as a engineer. He's missing his baby already so you can bet he'll be straight into it once he's sorted out the Indonesian dilemna ;D.
Pretty piss weak if you ask me. Is this any way to show his commitment to this project. >:(
I expected better!!
Sorry Jeff, I've let the team down, I feel terrible....
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and so you should pete....lol
hope work goes well
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Finally back home and working on the CD bike. Made some alloy sidecovers
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00047.jpg)
Painted them
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00121.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00122.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00127.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00128.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00132.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00134.jpg)
And the tank
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00123.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00124.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00125.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00126.jpg)
Then cleared
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00153A.jpg)More soon hopefully
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Nice 8)
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Good work Pete, I'm jealous.
My project has stalled, but that's a whole other story.
If the rider pull's out I could be tempted. ;D
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Brilliant Job. Very inspiring 8) 8)
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very, very nice. Did you roll a bead in those sidecovers?
Tank looks great too
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Nice work pete,will you be home for C/d? Hi to jackie
Got freddy Jones flying in for the world speedway bikes round at western springs
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sexy tank painting, wish i was able..
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very, very nice. Did you roll a bead in those sidecovers?
Tank looks great too
Didn't roll a bead in the sidecovers, just welded a return on the top to tuck in under the edge of the seat. The alloy is 2mm so just rounded the edges both sides so they aren't sharp.
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Put the bottom end together (with the new rod kit because of the DT/YZ length issue) which all went well. The YZ cylinder I bought from the states last year had a bore and piston that were like new, but the rings were completely worn out. Didn't think much of it until I started to clean up the cylinder for assembly and noticed that when it was bored last the ports hadn't been chamfered. Got the trusty angle grinder and fixed that problem.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00136.jpg)
Powdercoated the springs a bright yellow that I had, which I thought might be a bit much but they actually look ok (I think).
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00141.jpg)
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Nice work pete,will you be home for C/d? Hi to jackie
Got freddy Jones flying in for the world speedway bikes round at western springs
Home for CD for sure. Me and my brother and our sons are coming over for the skids too Mike. I'm the only one with a Kiwi passport though so they mightn't get in.Good work Pete, I'm jealous.
My project has stalled, but that's a whole other story.
If the rider pull's out I could be tempted. ;D
Not a problem Steve.
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I've had to go away for work for a couple of weeks, but here is the frame mocked up with the tank and sidecovers before they were cleared. Thanks to Vandy for the colour scheme.
The lines really aren't wavy like they appear in the photo. Anyone have any idea why this happens????
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00142.jpg)
I picked up a nice little Kawasaki whipper snipper from the local tip which will be the basis for the replica blender. Got to keep Bazza happy ;D
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00149.jpg)
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Almost finished. Just have to paint and fit the airbox, fit the fuel tap and fuel lines and give it a run.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00172.jpg)
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BLOODY HELL Pete!
that thing looks frikk'n awesome!
good to see your talent not going to waste.
was the tank painted with a gun? or from a can?
very nice 8)
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Look forward to a cool one in the blenda pete, good to have a cold one with you last saturday after the speedway,while dising the asian driver parking and watching the Kiwi triple "U" turn.
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BLOODY HELL Pete!
that thing looks frikk'n awesome!
good to see your talent not going to waste.
was the tank painted with a gun? or from a can?
very nice 8)
Thanks Mick and thanks for the engine, gearset, head and colour scheme.
Just sprayed with a gun using some left over acrylic lacquer that I had. Midnight black and Maico yellow - hope that makes it handle ;D
Look forward to a cool one in the blenda pete, good to have a cold one with you last saturday after the speedway,while dising the asian driver parking and watching the Kiwi triple "U" turn.
Bit of a freakshow at that pub Mike.
Need to get started on the blender next. Probably take the Jawa one as well up to CD9 to keep Jonesy happy :D
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Looking bloody good Pete.
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The lines really aren't wavy like they appear in the photo. Anyone have any idea why this happens????
I'm not a computer expert but I've found it's to do with the size of the photo you upload/link to. You don't need a full-on HD photo, just reduce them down in quality (pixels) to about a 100k-ish pic before you upload.
Bike looks awesome btw, really nice work
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The lines really aren't wavy like they appear in the photo. Anyone have any idea why this happens????
I'm not a computer expert but I've found it's to do with the size of the photo you upload/link to. You don't need a full-on HD photo, just reduce them down in quality (pixels) to about a 100k-ish pic before you upload.
Bike looks awesome btw, really nice work
Thanks for the tip mainline, I'll give it a try on the next photos.
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Don't worry about bloody photos-get into the next project :D :D :D
Seriously well done mate.
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Finally got the bike finished - far too many distractions. Made a pointer so the ignition timing could be checked with a strobe..
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00192a.jpg)
Got the airbox and dirt shield painted and installed and managed to fit the Kevlar credo in..
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00209a.jpg)
Gave it a run up the street and it's certainly quick.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00215a.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00204a.jpg)
Can't wait for CD9 to see if it was worth the effort and the cost (final tally $1137) ;)
Need to get started on the blender next....
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Pete good to see the Klub Kevlar motto under the guard,very stylish
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Very nice and inspiring for my upcoming project :)
Any chance of getting the pictures from the first few pages uploaded again??
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Very nice and inspiring for my upcoming project :)
Any chance of getting the pictures from the first few pages uploaded again??
Not real sure how to do that - perhaps someone can give me some clues...
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Still amazed by how much skill you have put into that bike. I hope one day I can do something like that.
Regarding the pictures have you deleted them from the site that you have them parked on :-\
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was it the one with the kawasaki KLR frame ? sea4rch that it was on here
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Picked up an old CT3 Yamaha from a mate for free. It had been sitiing outside long enough to rust the left hand handlebar off, but aside from seized brake cams it is in surprisingly good condition. This being the case, I've decided to try and turn it into an el-cheapo trials bike for classic dirt, with a budget of $600
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00242.jpg)
I've cut and shut the frame everywhere and ended up with a bike that is very similar to a TY175, but with a bit more ground clearance, slightly longer wheelbase and a steeper head angle - traits that are all said to improve the TY.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00270.jpg)
Next is to narrow and lengthen the CT3 tank and make up the footpeg plates. Following some good advice from JC, I'm after a set of MX125 triple trees. They have more offset and will reduce the trail to somewhere near the optimum for a trials bike.
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Once again you're putting the rest of us to shame Pete, good work.
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yep, nice effort
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Bugger you Pete..The contest for the trickest bike in the Kevlar Kompound at CD9 just got seriously interesting! ;D ;D ;D
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pete dont forget the smaller version we talked about over a sherbit at the auckland speedway!!
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totally impressed yet again Pete.
i've been riding a bit of trials this year on my TY175 and have seen quite a few "home specials" in the twin shock class, TS250, later DT175 converted to twinshock, a CT honda AG bike thing to name a few. the port specs on that thing of yours will be pretty close to TY specs as is. a 22mm carby would be nice ;)
but you do realise you'll need to make 3 pipes as the first 2 will be crap :D
great idea :)
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Bugger you Pete..The contest for the trickest bike in the Kevlar Kompound at CD9 just got seriously interesting! ;D ;D ;D
I think some of the tackle you're getting ready will set the bar pretty high Mark. We'll have a bunch of Yamahas between us though.
pete dont forget the smaller version we talked about over a sherbit at the auckland speedway!!
Running out of time Mike, but I've still got backup. ;D
totally impressed yet again Pete.
i've been riding a bit of trials this year on my TY175 and have seen quite a few "home specials" in the twin shock class, TS250, later DT175 converted to twinshock, a CT honda AG bike thing to name a few. the port specs on that thing of yours will be pretty close to TY specs as is. a 22mm carby would be nice ;)
but you do realise you'll need to make 3 pipes as the first 2 will be crap :D
great idea :)
The pipe is the biggest worry Mick. No-one seems to have any idea how a trials pipe actually works. Not really sure what to do at this stage, so I'll push on with the rest of it, and leave the pipe until last.
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I've logged in..so how come I cant see any of these photos..
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My thoughts are that the pipe will work pretty well as it is. And it looks ok for the era.
Having said that, the Villiers/Bantam I rode at the Nats(MX) was set up for trials and has a straight pipe into the front half of a hotdog muffler that is then weld into the second half which seems to be turned around (reveresed) Works ok too.
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Petes pipes are a work of art
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Trials pipes ???
not that i'd know but i'd go for a long header section, long divergent cone, belly section optional with a strongly tapered baffle cone.
plenty of tourque but not much over rev.
maybe a smallish stinger diameter?
something like that for a starting point.
an upcoming project for me is to put a DT100 motor into a TY175 roller which will need a pipe also,
so i'll be watching with interest Pete.
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Once again you're putting the rest of us to shame Pete, good work.
Yeah, that's exactly what I was thinking too Steve ::)
but on the other hand I love seeing the ongoing productions of Pete's art work :o :o
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Trials pipes ???
not that i'd know but i'd go for a long header section, long divergent cone, belly section optional with a strongly tapered baffle cone.
plenty of tourque but not much over rev.
maybe a smallish stinger diameter?
something like that for a starting point.
an upcoming project for me is to put a DT100 motor into a TY175 roller which will need a pipe also,
so i'll be watching with interest Pete.
My thoughts are that the pipe will work pretty well as it is. And it looks ok for the era.
Having said that, the Villiers/Bantam I rode at the Nats(MX) was set up for trials and has a straight pipe into the front half of a hotdog muffler that is then weld into the second half which seems to be turned around (reveresed) Works ok too.
Now I'm confused. I can't use the standard pipe as it is rusted out, but I could model it off it, or the TY pipe, or just start from scratch with something like Vandy says. ??? ??? Have to give it some more thought...
Got some work done over the weekend. Made up the rear shock mounts and tacked them in place. Made up the footrest brackets and rear brake pedal and rod. Dropped the springs out of the forks so I can see how much clearance I've got for the pipe, which turned out to be plenty. The kickstarter is a bit of a problem, even a TY one won't clear the brake pedal so I'll probably use the original and position it forward and kick onto the footest, a la Bultaco.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00283.jpg)
Also cut about 25mm out of the tank width and made up a base for it and tacked it in place. Machined up the filler neck to suit a TY style filler cap and welded it in.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00288.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00287.jpg)
Not sure what the tank will look like, but I'll know when I mock the bike up.
Vandy, if you get some time would you be able to measure the offset in your MX125 forks for me? Thanks. You need to start thinking about a colour scheme for this one too ;D
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Vandy, You need to start thinking about a colour scheme for this one too ;D
easy Pete,
TY250D Blue ;)
i'll measure the triples tomorrow and put it up here but it's possible it's pretty close to what the CT3 would be.
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I was looking at my Ossa Explorer pipe yesterday and as was said in the thread above, there isn't much 'expansion box' about them, just more like a couple of bits of pipe with a square-ish 'box' in the middle. Then a muffler banged on the end! Not sure how they make power out of them at all.
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Here's some 30mm Yammie triple info Pete.
i do have some spares depending, so let me know which set~up you like and i may be able to help.
Note:- "old" AG175 is the good old Orange tank we all knew as kids ;D
"new" AG175 is the later blue model with leading axle forks and laid down shocks.
(http://i1035.photobucket.com/albums/a438/vandy010/ozvmx%20stuff/30mmtripleclampoffsets.jpg)
also, i found this in my computer.it may help, even if it is from a modern trials bike.
just disreguard my spelling mistakes ;D
(http://i1035.photobucket.com/albums/a438/vandy010/ozvmx%20stuff/TrialsExhaustIdea.jpg)
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I was looking at my Ossa Explorer pipe yesterday and as was said in the thread above, there isn't much 'expansion box' about them, just more like a couple of bits of pipe with a square-ish 'box' in the middle. Then a muffler banged on the end! Not sure how they make power out of them at all.
Ditto my hand made Maico trials bike. There doesn't seem to be a lot of science in the exhaust design but the bike performs really well in trials situations so the original builder must have done some form of exhaust research. I had a bit of a look through A. Graham Bells 'Performance Tuning in Theory and Practice' bible and there's not a mention of trials exhaust design.
(http://i333.photobucket.com/albums/m392/cherie_jones/Maicotrialsfirko.jpg)
Pete..As far as the colour scheme goes, I reckon the original Yamaha design would look cool. I've got half a litre of original Candy Apple Tangerine Yamaha paint left over from the DT1 from Hell that I'll give you when you come up to get the DT2MX. You can buy the CT3 stripe kits from Speed and Sport on eBay http://www.ebay.com/itm/YAMAHA-AT3-CT3-TANK-COVER-DECAL-GRAPHIC-KIT-LIKE-NOS-/360222833737?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item53def43c49 (http://www.ebay.com/itm/YAMAHA-AT3-CT3-TANK-COVER-DECAL-GRAPHIC-KIT-LIKE-NOS-/360222833737?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item53def43c49)
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I've just pulled my garden shed apart looking for the swingarm off the DT1 from Hell when I came across a silencer/pipe mid section from a Honda TL125 that I'll gladly donate Pete. I know it's off a 4 stroke but you never know with these things. I also found the Telesco shocks I'd promised Jerry for his Pomeroy replica but still no swingarm ??? ??? ??? ???
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According to those figures the AG175 should steer just like an MX124---yep, they got that right---they both steer like crap :D :D :D :D :D :D
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I was looking at my Ossa Explorer pipe yesterday and as was said in the thread above, there isn't much 'expansion box' about them, just more like a couple of bits of pipe with a square-ish 'box' in the middle. Then a muffler banged on the end! Not sure how they make power out of them at all.
This is what is confusing - doesn't seem to be a lot of science. or we're missing something. ??? ???Here's some 30mm Yammie triple info Pete.
i do have some spares depending, so let me know which set~up you like and i may be able to help.
Note:- "old" AG175 is the good old Orange tank we all knew as kids ;D
"new" AG175 is the later blue model with leading axle forks and laid down shocks.
Thanks very much Mick, you went to a lot of trouble there - much appreciated. The CT triples are about 48mm offset so a set with 60mm offset would be good. The MX125 ones are the go as they are aluminium. There's a set on ebay for about $85 to my door from the US, which isn't too bad.
With regards to the pipe, I guess I'll go with something similar to that Beta one. It would be nice to apply some science, but in the absence of that, I might see if I can patch the original CT pipe up so at least I can have baseline to start with, otherwise I'll never really know.
TY 250 blue, or Mark's kind offer of original paint? Both good ideas, but as I am absolutely hopeless with colour schemes, I'll let that sit for a little while.I was looking at my Ossa Explorer pipe yesterday and as was said in the thread above, there isn't much 'expansion box' about them, just more like a couple of bits of pipe with a square-ish 'box' in the middle. Then a muffler banged on the end! Not sure how they make power out of them at all.
Ditto my hand made Maico trials bike. There doesn't seem to be a lot of science in the exhaust design but the bike performs really well in trials situations so the original builder must have done some form of exhaust research. I had a bit of a look through A. Graham Bells 'Performance
I've been through it too Mark. The principles could be applied, but I think it might be rather long, which I guess isn't a problem. I can curve down to the swingarm from the tank as the little CT frame has a single backbone, which leaves enough room either side.
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(http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash3/532154_10151018306010909_1666779198_n.jpg)
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i'm not real sure that'd work in a Trials section Freaky...
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You haven't watched freaky ride much have you Vandy-he'd just hold it flat!! :D
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Hey Pete....those TY triple clamps arrived today. I was going to try them on the Hindall flat tracker (much less offset) but I've since picked up as set of trick billet 35mm triples so I'll probably use them. They're wider pitch for the fatter Maxxis tyres too....so, TY clamps for Pete.
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Pete, those MX triples will give you much better trail spec - close to TY250
I also went thro Bell, Jennings, Robinson & Irving & none of them left me any the wiser for trials exhausts, tho Robinson did confirm that longer header & larger overall volume move the power down lower. One suggested that, since the sound waves depend on very fast opening of the ports, the sound waves aren't very strong (or significant?) at low engine speeds. That would be even more so on trials spec w lower exhaust ports were the piston speed at port opening is also lower
A few trials models did go the expansion chamber route - loooong & convoluted - circa early 80s (242/304 Cota, Ossa Gripper, Beta TR34), but most seem to just have a long header dumping into a 'box', often of indescriminate shape (whatever fit the body work?). I read recently in Trials Mag that most modern manufacturers have gone back to that.
I did a quick check on an IWT program & you'd need a tuned length of about 1300mm for 6000rpm & 170deg exh duration, but that was assuming 500deg C whereas trials engines probably run at lower temps where the sound waves also travel slower. By comparison, a TY175 pipe is about 950mm! (???)
TY header length is about 26" & diffuser & midsection about 12" combined (sorry for mixing inches & mm). By the look of the weld marks there appears to be 2 internal baffle plates, the 1st in the diffuser section at about 20-25deg (to the horizontal) & the 2nd in the 'belly' at about 45deg. There's no real rear cone to speak of, just an 'end wall' to close it off & attach the tail-pipe.
Its almost as if those baffle plates are in there to break up what little sound wave effects are there (??) so theres no real "tuned length" for a returning +ve pulse.
The Beta one Vandy posted also appears to have almost no rear cone to speak of. Header looks slightly tapered tho for whatever reason.
Having said that, the WES aftermarket Ty exhausts do appear to have diffuser, mid-section & baffle cone, still w a short overall length. Some Fantic ones look similar, tho there's no guarantee of the internal shape cos of the perforated & packed inner 'skins'. I have seen a Fantic 'diffuser cone' sectioned (cut-away) & its plain perforated tube (parallel walled) inside
All rather confusing. Nothing is very conclusive ???
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Hey Pete....those TY triple clamps arrived today. I was going to try them on the Hindall flat tracker (much less offset) but I've since picked up as set of trick billet 35mm triples so I'll probably use them. They're wider pitch for the fatter Maxxis tyres too....so, TY clamps for Pete.
I'm not sure about TY175 triples but TY250 triples have a few degrees difference between the steering tube and forklegs. The forklegs have more rake to them than the steering tube. This effectively increases the offset from what the triples measure.
More so as the forkleg length is increased.
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i followed you through most of that JC and tend to agree.
it's all a bit grey............... ???
and given all the variations i've seen on homemade trials specials, then to talk to the owner/rider and they all seem to have not known what to do but are happy enough with thier results.
i reckon it's just comitting to an idea and see where it leads.
pipes ???
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Here's an article on a TS 125 trials conversion from Cycle magazine 1973. Interesting looking pipe.
(http://i1084.photobucket.com/albums/j413/vmxrider/img058.jpg)
(http://i1084.photobucket.com/albums/j413/vmxrider/img059.jpg)
(http://i1084.photobucket.com/albums/j413/vmxrider/img060.jpg)
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i'm not real sure that'd work in a Trials section Freaky...
as they say its "all about the style "
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With your exhaust mods you can always put a potato canon on it for around the campfire later ;D
(http://vft.org/ForSaleWanted/06Jun22-MXBultacoFrontera.jpg)
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That Bully is the bees knees for shooting tee shirts in to the crowd
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OK, so a loong time ago I read an article in (I think) Dirt Bike Mag or Motocross Action, about how exspansion chambers work.
Now, if I remember correctly, they mentioned that to get it in your head, you have to imagine that the gasses coming out of the exhaust port are like a tribe of indians being chased by cowboys (or was it the other way about-not too sure but the result is similar) So, those guys are being chased and they are making alot of whooping and hollering, out of the port and into the chamber. The chamber is like a box canyon and after a bit the leading indians(cowboys) get near to the end and it starts to get squeezy, so some of them turn around and start back up the canyon towards their mates(and the enemy) That my friend is called back-pressure and a two-stroke wont work too well with out it.
Now on a trials bike, it's all happening alot slower so not so much whooping and no hollering, so maybe,just maybe, they aren't indians at all but rather Ninjas. This could explain why trials bikes creep over rocks and logs and sneak through the bush.
But it still explains nothing about how to build a pipe for a trails (Ninja) bike!
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Heres something ..Have you looked at the exhaust replacements that Sammy Miller Products have to offer for The TY series Yamahas..They are a Stainless Header pipe and Aluminium Chamber and silencer, Ive got one on my TY250..Shouldnt be to much of of a problem to copy they are a very basic design..Cheers and have fun..
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I'm overloaded with information here. I think, based on the general consensus, that I should either just build a pipe that fits, with a minimal amount of whooping and hollering, or as Freaky is alluding to, give up and go back to building motocross bikes. Some dimensions on the Sammy Miller pipe would be good thanks Stinger, just to see what they were thinking. Having said that, JC has unearthed a few trials pipes cut in half (courtesy of trials guru David Lahey) and they have a straight perforated pipe inside. The lawn mower muffler is looking better all the time. That little Suzuki certainly looks the goods, but it has a very strange pipe indeed.
Managed to get some other work done on the bike. Made up and fitted a sidestand and modified the back brake backing plate to allow the torque arm to tuck up further close to the swinging arm. Bit of a setback with the back brake as the brake pivot is too far below and behind the swinging arm pivot point resulting in very inconsistent brake pressure during swinging arm movement. I'll either move the pivot closer to the swinging arm pivot or fit a cable brake. Gives me something to think about to take my mind off the exhaust :D
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00294.jpg)
Hey Pete....those TY triple clamps arrived today. I was going to try them on the Hindall flat tracker (much less offset) but I've since picked up as set of trick billet 35mm triples so I'll probably use them. They're wider pitch for the fatter Maxxis tyres too....so, TY clamps for Pete.
Thanks very much for your kind offer Mark, but as Brent says they have an odd rake offset to the steering head. Also, I think the TY250 forks are 34mm, whereas I have 30mm forks, with brand new freebie tubes. I think I'll go with John and Vandy and get the MX125 triples. Much appreciated though.
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Be prepared to move the frontpegs after your first ride, they look a bit further back than ideal. If they're too far back the front sledges when turning
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The exhausts SM Products sells are the WES ones. Most of them have the internal perforated skin packed w f'glas but I'm not certain if they all do. May just be parallel tube inside also.
Pete, a couple of suggestions on colour scheme - perhaps the Peter Paice blue scheme in VMX #50 which looks even nicer in person than in the mag, or whatever yr own CT2/3 was back in the day if you still 'connect' w that bike. Or the yellow & black 'speed-block' scheme looks nice on trials Yams too. I'll sift thro my Ty pics saved from the net & email you some alternatives.
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Any particular reason the kick-stand is on the right?
Is it a 'trials' thing, a southern European thing or are all the trees at a trial taken by a broken down Bully?
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havn't you got a job Vaughan?
sidestand is on the right because the left side gets "busy" with the chain and possible tensioner.
it's a clearance thing dude.
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I'm waiting for another VNXer to come in a buy/beg a bit of pipe that they don't want me to cut/bend/weld ("I can do that myself") :D :D :D
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Thanks very much for your kind offer Mark, but as Brent says they have an odd rake offset to the steering head. Also, I think the TY250 forks are 34mm, whereas I have 30mm forks, with brand new freebie tubes. I think I'll go with John and Vandy and get the MX125 triples. Much appreciated though.
No worries Pete....I think they'll be a good experiment for dirt track, perhaps on the Hindall tracker if I use the billet clamps on the Trackmaster XS650.
I had another read of Bells book in bed last night and unfortunately JC and everyone is right...he doesn't get into trials systems much, if at all. While reading Bells book I had an inkling from long ago of reading something by Gordon Blair (or maybe it was Jennings) on trials exhaust but I've just spent over an hour Googling for it with no result.
Having said that, JC has unearthed a few trials pipes cut in half (courtesy of trials guru David Lahey) and they have a straight perforated pipe inside. The lawn mower muffler is looking better all the time.
If that's the case, perhaps my TL muffler might not be as silly as it originally seems. It's here for the taking. I'd be tempted to cut my Maico "expansion" box to see what's in there but I'm out of gas to weld it back together ;D.
Here's a PDF file of Dr Blairs book. It probably doesn't solve Pete's immediate problem but it's an interesting read for technophiles.
http://www.media.rmutt.ac.th/media/e-book/Engineer/Automotive/The%20Basic%20Design%20of%20Two%20Stroke%20Engines.pdf (http://www.media.rmutt.ac.th/media/e-book/Engineer/Automotive/The%20Basic%20Design%20of%20Two%20Stroke%20Engines.pdf)
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Ditto my hand made Maico trials bike. There doesn't seem to be a lot of science in the exhaust design but the bike performs really well in trials situations so the original builder must have done some form of exhaust research. I had a bit of a look through A. Graham Bells 'Performance Tuning in Theory and Practice' bible and there's not a mention of trials exhaust design.
Modern trials pipes are calculated to the mm, just because it looks simple doesn't mean it is. They are hard to get wrong , a long parralel header will help them pull off the bottom well.
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Be prepared to move the frontpegs after your first ride, they look a bit further back than ideal. If they're too far back the front sledges when turning
That's the angle of the camera shot making it appear like that Tony. The footrests are actually only 15mm further back from the front axle than TY175 pegs and, because my swingarm is a little longer, are further away from the rear axle than the TY. Still, if they are too far back its's very simple to move them forward.
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I suspected that camera angle may have had something to do with it, best part about using plate mounted pegs is ease of adjustment if needed.
Standard TY175s are too light in the front end & benefit from lengthening the swingarm
I could take some measurements of position relative to swingarm pivot on my sherco & TY250c when I get back to NZ from the gold coast in the weekend if that helps out to compare
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I suspected that camera angle may have had something to do with it, best part about using plate mounted pegs is ease of adjustment if needed.
I could take some measurements of position relative to swingarm pivot on my sherco & ty250c when I get back to NZ from the gold coast in the weekend if that helps out
That'd be great, thanks.
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Modern trials pipes are calculated to the mm, just because it looks simple doesn't mean it is. They are hard to get wrong , a long parralel header will help them pull off the bottom well.
Lozza, tell us more. The long parallel header is a given, tho some more modern designs appear to have a slight taper for about half its length.
But we want to know about the design of the so-called "mid-box" specifically for trials. We all have a decent grasp of expansion chamber design for MX, enduro etc, but none of us can find anything specific to trials bikes design.
If you apply the usual expansion chamber design criteria, adapted for broad powerband & low-end power, you get a design much much longer than the typical trials exhausts. A couple of manufacturers went that route circa '80 but it didn't last.
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it's easy they 'smear' the return wave (it's not sound either more later on that) and make a low amplitude pulse.
If the taper has been incorporated into the header that's needed due to the better transfer geometry of modern engines.
An exhaust pulse has 3 parts. Pressure, sound and particle, pressure wave moves fastest, then sound and last the particle. Practicaly they are hard to separate in a pipe, easy with transducers
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it's easy they 'smear' the return wave (it's not sound either more later on that) and make a low amplitude pulse.
If the taper has been incorporated into the header that's needed due to the better transfer geometry of modern engines.
An exhaust pulse has 3 parts. Pressure, sound and particle, pressure wave moves fastest, then sound and last the particle. Practicaly they are hard to separate in a pipe, easy with transducers
So he should be using transducers not a chamber? ;D
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it's easy they 'smear' the return wave (it's not sound either more later on that) and make a low amplitude pulse.
Which one? The -ve return wave or +ve one?
it's not sound either more later on that
:-[ duh, yes of course; pressure wave. Seniors moment!
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I like the idea or wooping and hollering. I think i need the drugs EML is on. lets play cowboy and indians
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it's easy they 'smear' the return wave (it's not sound either more later on that) and make a low amplitude pulse.
If the taper has been incorporated into the header that's needed due to the better transfer geometry of modern engines.
An exhaust pulse has 3 parts. Pressure, sound and particle, pressure wave moves fastest, then sound and last the particle. Practicaly they are hard to separate in a pipe, easy with transducers
So he should be using transducers not a chamber? ;D
Just where you put it makes all the difference Jeff ;)
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it's easy they 'smear' the return wave (it's not sound either more later on that) and make a low amplitude pulse.
Which one? The -ve return wave or +ve one?
it's not sound either more later on that
:-[ duh, yes of course; pressure wave. Seniors moment!
I left a hint in there for ya ;D There is no negative return wave only positive.
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Chmaber design has pretty much been summed up by others, long headers for bottom end and a long overall length for low revving motors, the ‘box’ is about faking long length other wise you wouldn’t be able to fit the pipe on bike. Not aware of any formula to calculate the box
It all depends how fussy you are, do you want to create something state of the art or just something that will work reasonably well.
If your only after 'reasonably well’ then take any 125 MX chamber and add 5” into the header length and another 2” into the mid section.*
* Normal disclaimer, if it works good I will take credit but if it sucks then I will remind you not to believe everything you read on the net.
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* Normal disclaimer, if it works good I will take credit but if it sucks then I will remind you not to believe everything you read on the net.
:D :D :D
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Chmaber design has pretty much been summed up by others, long headers for bottom end and a long overall length for low revving motors, the ‘box’ is about faking long length other wise you wouldn’t be able to fit the pipe on bike. Not aware of any formula to calculate the box
It all depends how fussy you are, do you want to create something state of the art or just something that will work reasonably well.
If your only after 'reasonably well’ then take any 125 MX chamber and add 5” into the header length and another 2” into the mid section.*
* Normal disclaimer, if it works good I will take credit but if it sucks then I will remind you not to believe everything you read on the net.
Thanks Geoff,
Certainly don't need state of the art, "reasonably well" would do me fine considering I've never ridden trials ;D
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I reckon the stock CT3 pipe might be just the ticket considering it's designed for a pretty broad application.
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I left a hint in there for ya ;D
Thats what I tho't you meant, but....
There is no negative return wave only positive
That goes against everything published on expansion chamber design. As I understand it, the -ve one is reflected too, off the open end of the header & diffuser
the ‘box’ is about faking long length
That is a very useful bit of info relevant to trials exhaust design Geoff. Many thanks
Jennings does give a formula for natural frequency in a 'flask' w pipe inlet - effectively what most trials exhausts are
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I reckon the stock CT3 pipe might be just the ticket considering it's designed for a pretty broad application.
I reckon so too Mark. I rode a lot of CT's in their day, and remember them having a nice even power curve and not pipey at all. I'd like to try it with the CT pipe to at least establish a baseline so I know where I'm going, before I start making too many changes.
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Back from holiday on gold coast & went out to garage before it got too cold, took some measurements of the modern bike & my TY250-only approx as it's parked behind the CZ & YZ465
Sherco measurements are
Front of footpeg to swingarm pivot 65mm
Swingarm length 530mm
Front of footpeg to rear axle 440mm
Front of footpeg to front axle 900mm
TY250C twinshock approx measurements
Front of footpeg to swingarm pivot 0mm
Swingarm length 485mm
Front of footpeg to rear axle 465mm
Front of footpeg to front axle 930mm
The TY is too light in the front (lifts too easily even with no compression) & is about to get lengthened by 50mm to bring the bike back to standard wheelbase which is possible due to the steering having been altered sometime in the 90s by the owner's son
Hope these numbers help out with getting the footpegs in the right position
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Finished narrowing the tank and made the front and rear mounts. Bit of good old Bondo and you'll never know.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00296.jpg)
Modified the rear brake pedal to get the rod pivot close to the swingarm pivot and it now works well. Fitted up some MX125 triples (thanks Vandy) which have more offset than the original CT triples, which will decrease the trail a bit. They will also extend the wheelbase marginally so I may pull the head angle back a little more. which will also decrease the trail. Will make the seat next and then start on the pipe ??? ???
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00297.jpg)
Back from holiday on gold coast & went out to garage before it got too cold, took some measurements of the modern bike & my TY250-only approx as it's parked behind the CZ & YZ465
Sherco measurements are
Front of footpeg to swingarm pivot 65mm
Swingarm length 530mm
Front of footpeg to rear axle 440mm
Front of footpeg to front axle 900mm
TY250C twinshock approx measurements
Front of footpeg to swingarm pivot 0mm
Swingarm length 485mm
Front of footpeg to rear axle 465mm
Front of footpeg to front axle 930mm
The TY is too light in the front (lifts too easily even with no compression) & is about to get lengthened by 50mm to bring the bike back to standard wheelbase which is possible due to the steering having been altered sometime in the 90s by the owner's son
Hope these numbers help out with getting the footpegs in the right position
Thanks very much for that Tony. i've just checked mine and the dimensions are:
Front of footpeg to swingarm pivot 55mm
Swingarm length 460mm
Front of footpeg to rear axle 395mm
Front of footpeg to front axle 935mm
The numbers are a bit different but perhaps you (or someone) can tell me what the implications will be.
Cheers,
Pete.
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Looking at your figures suggests that your weight will be to rearward which generally causes the front to plow on in turns rather than bite, your pegs are almost as close to the front axle as on my TY but due to the very short swingarm are closer to the rear wheel
Most kits for TY footpegs end up with them being just behind the pivot which is a bit further back than standard
I'd be lengthening your swingarm to help with keeping the front down, I had major issues last time I rode at Kaikoura with the front being too light on climbs even though the engine was seriously sick, could turn motor over by gripping end of crankshaft with the plug still in. David Lahey has put up some very good photos etc on trialscentral & trials australia detailing how he does it to his TY175s
Looking at the figures for my Sherco shows how the engine must be closer to the front wheel as even with a longer swingarm the wheelbase is shorter. Modern bikes seem to be all about mass centralisation which is where the very low seat comes from
Standard TY wheelbase is listed at 1295mm which must be a misprint as I work mine out as 1395mm with reduced rake, always possible that I measured wrong
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Pete, brake arrangement looks good, as does tank.
Tony, I think you've definitely measured wrongly.
1395mm is typical MX wheelbase. TY250C std w'base is definitely 1295mm.
Mine is 1300 w the axle back a little on the adjusters.
Other measurements on my std TY250C are:
Swingarm length 380mm
Front of peg to rr axle 380
Front of peg to fr axle 920
Seems to me Pete's in the right ballpark
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I have been pondering GMCs post-----not the bit about the disclaimer as that's a given :D
He mentions that "faking long length (where have I heard that before?) otherwise you wont fit it in" (again-where have I heard that before?) but then concedes that he is "not aware of any formula"
By 'faking length' and turning it into diameter-is that not the 'formula'?
i.e. shorten header by 2'' but make it 4'' diameter instead of 3''???
But then he goes on to say "add 5''s into the header and 2''s into the middle of an MX125 pipe". Not sure about you but if I added 5''s to my header I'm pretty sure it wouldn't fit anywhere even without adding 2''s to the gurth--just sayin' ::)
But then if you look at the modern 2 smoker pipes (2000 on) they are very short and fatten up very quickly.
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There is no negative return wave only positive
That goes against everything published on expansion chamber design. As I understand it, the -ve one is reflected too, off the open end of the header & diffuser
yes there is a reflection off the diffuser and header BUT it is still postive pressure,reflected from the outbound exhaust wave. Again all simple to see on a basic simulator, what you see is a depression with a small hump or not quite as big depression.
There is a formula for everything including box mufflers(had to do them for chainsaws in stock classes). The box isn't faking length, that's what a KIPS/ATAC/AEC valve does, if that's all there was to it there would just be a big resonator 'somewhere'.
I think the pipe would be hard to get wrong and a look inside a box of a trials pipe might have some clues.
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I have been pondering GMCs post-----not the bit about the disclaimer as that's a given :D
He mentions that "faking long length (where have I heard that before?) otherwise you wont fit it in" (again-where have I heard that before?) but then concedes that he is "not aware of any formula"
By 'faking length' and turning it into diameter-is that not the 'formula'?
i.e. shorten header by 2'' but make it 4'' diameter instead of 3''???
But then he goes on to say "add 5''s into the header and 2''s into the middle of an MX125 pipe". Not sure about you but if I added 5''s to my header I'm pretty sure it wouldn't fit anywhere even without adding 2''s to the gurth--just sayin' ::)
But then if you look at the modern 2 smoker pipes (2000 on) they are very short and fatten up very quickly.
You shouldn’t think about things too much, it will only hurt, especially if you think too hard about something I wrote.
The best way to fake length is in the dark, as for pipe design you can simplify a chamber down to three parts…
Length
Diameter
Angles
Length is easy, long pipes produce low revving motors and short pipes produce high revving motors.
Choosing diameters and angles is more complicated as they sort of go hand in hand with each other but in a nutshell, sharp angles produce abrupt power characteristics and shallow angles produce mellower power characteristics.
The ‘add 2” to the belly was meant for the length not the diameter.
The box / resonator will produce a flat torquey type powerband, and generally kill any wild top end, much the same as a long chamber. That’s why I suggested it as ‘Faking’ length. Apostrophe’s show that I use the word loosely for people to be able to grasp the concept.
Long headers produce good low end power so modern bikes don’t require this as much as they make up for it with power valves so modern pipes are designed more for top end power in comparison.
The only negative wave I have experienced is handing my wife money than waving her goodbye as she heads off to the shops.
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Pete, brake arrangement looks good, as does tank.
Tony, I think you've definitely measured wrongly.
1395mm is typical MX wheelbase. TY250C std w'base is definitely 1295mm.
Mine is 1300 w the axle back a little on the adjusters.
Other measurements on my std TY250C are:
Swingarm length 380mm
Front of peg to rr axle 380
Front of peg to fr axle 920
Seems to me Pete's in the right ballpark
Pretty sure I got the measurement wrong, was holding & leaning over the CZ to do it. Appears to be the swingarm that is wrong
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Got the seatbase made and shaped some foam ready to get covered
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00298.jpg)
Machined up a fuel tank cap that won't shrink
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00299.jpg)
Pulled the carby apart and it was in terrible shape inside. The pilot jet was stuck solid and no amount of penetrene, combined with heat, could remove it. As happens, the screwdriver slot in the top of the jet is no longer there, so I'm off to the wanted section to see if anyone has one that they might sell me.
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Whats model is your carb ? i have a box of early traily carbs , no gaurantee but would be happy to donate one to the project if i have one suitable .
Bill
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Hi Bill, thanks very much for your kind offer, I was lucky enough to get one locally
off rookie#1 that is the correct model.
Pete
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Got my pipe finished. No idea if it will work or not but I have looked at so many different pipes I'm confused, so this one is a combination of everything. I've probably got it totally wrong but I have plenty of oxy and plenty of sheetmetal ;D
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00314.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00324.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00323.jpg)
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One from the other side.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00320.jpg)
Have to go away for work next week so it'll be a push to have it ready for CD9. Hopefully the rest goes together OK.
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Got a one week reprieve from going away for work so I've managed to get the wheels built and the frame and tank painted. Hopefully on the weekend I can put the motor together then just have to finish the guards and muffler, ready for CD9. Don't know much about these trials bikes, but it seems to look something like one, so I hope it works OK ;D
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00339.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00340.jpg)
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lookin good Pete,all booked for C/d
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That looks terrific. The exhaust is especially cool.
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nothing like adding a bit of colour to the shed hey Pete :D
looks like it'll be worth it when its all done.
trials is good fun :)
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lookin good Pete,all booked for C/d
Looking forward to it Mike.
That looks terrific. The exhaust is especially cool.
Thanks Dave - -whether it works or not is another story.
nothing like adding a bit of colour to the shed hey Pete :D
looks like it'll be worth it when its all done.
trials is good fun :)
The colour's a bit loud Mick, but it was there :D. I can't wait to give it a run.
Started on the guards today. They both turned out to be very rusty, particularly where the reinforcing is underneath,
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00342.jpg)
so I went into the stash and found a front guard off a Harley softail (go ahead and take your cheap shots now ;D ;D) which was very similar to the CT3 guard, so it was just a matter of drilling the old mounts off the original guard and welding them onto the new guard.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00341.jpg)
Couldn't do anything with the back guard so I've ordered a Cappra fibreglass replica from Bron-Moto, which should fit OK. Still well under $600 and don't have to buy anything else that I can think of, luckily. I'd hate to spend more on this than I could buy a decent TY175 for ;)
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Started on the guards today. They both turned out to be very rusty, particularly where the reinforcing is underneath,
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00342.jpg)
so I went into the stash and found a front guard off a Harley softail (go ahead and take your cheap shots now ;D ;D) which was very similar to the CT3 guard, so it was just a matter of drilling the old mounts off the original guard and welding them onto the new guard.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00341.jpg)
Couldn't do anything with the back guard so I've ordered a Cappra fibreglass replica from Bron-Moto, which should fit OK. Still well under $600 and don't have to buy anything else that I can think of, luckily. I'd hate to spend more on this than I could buy a decent TY175 for ;)
Looks like you've solved the possible too light front end problem ;D
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Finally got the little trials bike finished - came in just under $600. I gave it a run yesterday and it seemed to work OK. Felt nice to ride with plenty of bottom end, but I'd like someone who knows to have a ride on it at CD9.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00382a.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00380a.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00371a.jpg)
The Cappra guard fitted up OK except the seat cutout was for the original Yamaha guard, so there's a bit of a gap. The Montesa indent in the guard was a good spot for a tuning fork sticker.
(http://i1258.photobucket.com/albums/ii534/yamaico/DSC00361a.jpg)
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Felt nice to ride with plenty of bottom end, but I'd like someone who knows to have a ride on it at CD9.
I think you will have quite a queue for that task ;D ;D WELL DONE!!!!
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Pete "its all about style"
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I wonder if I leave some of my crap outside his shed, will he turn that into magic as well???
Seriously BIG WELL DONE champ!! Talk about sows ear to silk purse!!
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Looks the goods Pete. Excellent job.
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I meant to say yesterday that it wont matter what it handles like because 99.9% of trials riding is the rider.
A good trials rider will ride anything anywhere at any time and show the rest of us how it should be done.
I could be on the best trials bike ever and still look like a chooka :D
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I'll swap you a ride on my Monty Cota 242 if you want 8) Somehow I think Toni Bou would even have trouble putting a '73 TM400 or original '82 YZ490 up a trials section ;D but the point of your statement is true as I have a good trials bike and often ask the observer while pinned under it "Is that a 5" :D ::)
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How did the trials bike go at CD?
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Do we know where the pics went from the flattracker build in the link on page 1 ?
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How did the trials bike go at CD?
Sorry Tony, bit late replying, but work has kept me busy. I didn't ride the bike much at CD9, as I spent most of the time on the 400. Montynut was kind enough to take it for a spin and said he liked it, but thought it could do with a little lower gearing, straighter handlebars and perhaps a bit more flywheel weight. It definitely needs a skid plate, particularly as the rear engine mount hangs low. Montynut can feel free to step in here and add anything I've missed.
Do we know where the pics went from the flattracker build in the link on page 1 ?
Not sure what happened to them mainline, as Firko hosted that build, but I still have them. I can repost them or put them on photobucket and post a link if you like.
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yeah id like to see the flat tracker pics as well as ive got a dt400h to do
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I hosted the photos of Petes flat tracker through Village Photos. When they went tits up, everything on the forum done through Village disappeared. Sorry for the inconvenience but who'd have thought that would happen?
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How did the trials bike go at CD?
Sorry Tony, bit late replying, but work has kept me busy. I didn't ride the bike much at CD9, as I spent most of the time on the 400. Montynut was kind enough to take it for a spin and said he liked it, but thought it could do with a little lower gearing, straighter handlebars and perhaps a bit more flywheel weight. It definitely needs a skid plate, particularly as the rear engine mount hangs low. Montynut can feel free to step in here and add anything I've missed.
Do we know where the pics went from the flattracker build in the link on page 1 ?
Not sure what happened to them mainline, as Firko hosted that build, but I still have them. I can repost them or put them on photobucket and post a link if you like.
That'd be great if you could, I'd really like to see the pics of the steering head mod again. Cheers
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These?
(http://i1258.photobucket.com/albums/ii534/yamaico/SD530403.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/SD530401.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/SD530402.jpg)
(http://i1258.photobucket.com/albums/ii534/yamaico/SD530406.jpg)
It's important that you measure the head angle with the bike sitting on a flat surface first, then decide what angle you want to come back to. You now have a difference so once you know this value it doesn't matter where you have the bike set up when you do the mod - just make sure you have the frame secured when you do it.
You probably need to shoot for somewhere around 25 to 26 degrees of head angle, 1400 - 1450mm wheelbase and 90 - 110mm trail. The weight bias should be about 52%/48% front to rear. These are numbers that work for me, so feel free to get a second opinion. ;D
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that's them, thanks for digging them up. Not sure what angle/wheelbase I'm looking at yet. This is a trials thing not a flattracker, I just remembered seeing the digital level in there and thought it was a pretty neat job. Thanks again
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Not only that but the level is a Husky. :D :D :D
Very clever work too.
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How did the trials bike go at CD?
Sorry Tony, bit late replying, but work has kept me busy. I didn't ride the bike much at CD9, as I spent most of the time on the 400. Montynut was kind enough to take it for a spin and said he liked it, but thought it could do with a little lower gearing, straighter handlebars and perhaps a bit more flywheel weight. It definitely needs a skid plate, particularly as the rear engine mount hangs low. Montynut can feel free to step in here and add anything I've missed.
I rode the Yammy. It has potential.
The gearing was too high and I found the power was too harsh off idle. This means it has a tendancy to stall easily and with no warning
I think it could possibly use a smaller carbie (it looked like a 26mm while a TY175 has a 22mm from memory) as the transition from throttle closed to throttle open unsettles the bike pretty badly.
The engine needs as much weight as possible added to the flywheel/crank to smooth out the power in the first 1/4 of throttle opening
The rear engine mount at present hangs up very easily but a good flat sump plate will reduce that.
I thought it could use longer shocks to lift the rear and increase the swingarm angle of attach.
The handlebars have a largish curve when trials bars are very straight to allow the rider to easily move their weight over the front
I know this all sounds like I have a massive list of problems with it but most are easily solved and were already in the pipeline. It the old story it is 90% there but the last 10% is trial and error
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How did the trials bike go at CD?
Sorry Tony, bit late replying, but work has kept me busy. I didn't ride the bike much at CD9, as I spent most of the time on the 400. Montynut was kind enough to take it for a spin and said he liked it, but thought it could do with a little lower gearing, straighter handlebars and perhaps a bit more flywheel weight. It definitely needs a skid plate, particularly as the rear engine mount hangs low. Montynut can feel free to step in here and add anything I've missed.
I rode the Yammy. It has potential.
The gearing was too high and I found the power was too harsh off idle. This means it has a tendancy to stall easily and with no warning
I think it could possibly use a smaller carbie (it looked like a 26mm while a TY175 has a 22mm from memory) as the transition from throttle closed to throttle open unsettles the bike pretty badly.
The engine needs as much weight as possible added to the flywheel/crank to smooth out the power in the first 1/4 of throttle opening
The rear engine mount at present hangs up very easily but a good flat sump plate will reduce that.
I thought it could use longer shocks to lift the rear and increase the swingarm angle of attach.
The handlebars have a largish curve when trials bars are very straight to allow the rider to easily move their weight over the front
I know this all sounds like I have a massive list of problems with it but most are easily solved and were already in the pipeline. It the old story it is 90% there but the last 10% is trial and error
I'm bitterly disappointed in the bike after having poured over $600 into it - what a money pit.
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I'm sorry if my comments were interpretted as all negative. My points were assuming the bike was to be a serious Classic Trials mount.
You indiacted at CD9 that it was more a bike aimed at someone starting out and as a trail bike with a 'trials' focus a bit like an Alpina or Montesa 172T then it is bloody perfect 8). Except the handle bars ??? couldn't handle them but that is personal preference. It is a shame you didn't have a ride on my Cota 242.
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I'm bitterly disappointed in the bike after having poured over $600 into it - what a money pit.
AJ and I sincerely hope you don't you spend that kind of money again Pete....you're creating an uneven playing field for us poor folk. Remember the challenge! ;D ;D ;D
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I'm sorry if my comments were interpretted as all negative. My points were assuming the bike was to be a serious Classic Trials mount.
You indiacted at CD9 that it was more a bike aimed at someone starting out and as a trail bike with a 'trials' focus a bit like an Alpina or Montesa 172T then it is bloody perfect 8). Except the handle bars ??? couldn't handle them but that is personal preference. It is a shame you didn't have a ride on my Cota 242.
Just joking, Montynut. ;D
No point me riding your Cota as I don't know one end of a trials bike from the other.
I'm bitterly disappointed in the bike after having poured over $600 into it - what a money pit.
AJ and I sincerely hope you don't you spend that kind of money again Pete....you're creating an uneven playing field for us poor folk. Remember the challenge! ;D ;D ;D
Someone told Jackie I was spending that crazy money Mark, so it's all over now. No more big budget bikes for me. "It's all about style" is now "It's all about denial".
I'm shattered....