OzVMX Forum
Clubroom => Twinshock Trials => Topic started by: Oldbiker on November 04, 2008, 01:02:04 pm
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We've seen all the other makes mentioned, but no Yamaha's!
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Yes there are hundreds of TY riders out there. There are probably no TY photos in that string because Yamaha TYs are not generally seen as rare or interesting as most people interested in VMX have seen them lots of times already.
I've been campaigning TY Yamahas in competition since they were new bikes and still think they are the bees knees if you want to win but because they are so commonly seen, I don't usually push the publicity on them, and have even taken to riding anything else just for a change.
If you want to see what sort of TYs are in use out there, heres a link to something you might find interesting. It's a very long forum string on the Trials Australia website with photos of mostly queensland-based twinshock trials bikes.
http://www.trials.com.au/phpBB3/viewtopic.php?f=16&t=2556
Regards
David Lahey
Yamaha TY nut
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Here you go. Brooweena Twinshock-only trial 2006.
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I've seen you on Trials.com.au feetup. you know me as Stu
I thought it may have been that the TY's are getting older they may show up here. I'd like to do the 2 day Classic Trial next year. Any idea where it will be held?
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Hi Stu. Thats a bit tricky having two names. You had me going there.
Which 2-day Classic are you talking about? There will be a Brooweena Twinshock and Classic-only 2 day at Brooweena (near Maryborough) again in winter and theres the Denman 2 day in June but I don't know which property it will be at.
We are cooking up the idea of another 2 day trial like Brooweena (ie Twinshock and Classic only) in 2009 but a bit further North (near Gladstone) but are only at the stage of asking potentially interested riders before we commit to running it.
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Seeing that I started with the boys from Denman many years ago(G'day Chappy!) I'd like to give the Denman 2 Day Trial a go. I know it will be bloody good weekend!
Gladstone is a bit far at this stage, but you never know!
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Hey David (feetup),
I've heard of you too. I grew up at Gladstone in the 60s & 70's but raced MX. Attended a few trials but never competed.
I heard of you a couple of years ago from someone else in vintage trials, but I tho't you were into sherpaTs & MARs.
I have the bones of a TY250A (frame, rusty forks, wheels, matching nos bottom end) that I've often wondered what to do with - complete it as a trials bike or turn it into an Alpina sort of bike.
If they're as good at trials as you say they are, maybe I should go that route
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Maybe someone on this thread can help me. Many years ago I swapped a carton of beer for a decrepit but running TY250A that has some nice mods like YZ wheels and modified reed valve setup. The thing that seperates this bike from others is the chrome swingarm and brake stays and distinctive metallic green and pearl white custom paint job that appears to have been professionally applied. Somebody told me that he thought the bike had been used for professional showground trick riding by somebody whose name he couldn't remember. It's now out of action, tucked away down at the farm after the kids decided that the petrol out of the SL125 would work in the TY. I eventually hope to get around to restoring it, maybe in the green and white scheme if we find that the bike had a part in history. If anybody has any memories of a cool looking green and white TY I'd love to know its history.
In the meantime I'll sort my Maico trials special and learn how to ride these trials things properly.
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Hi JC
So does that mean you are a real Gladstone local? I've only been here 13 years so can never be classed as real local being born elsewhere.
Seeing you were doing MX here way back then you probably rode at the MX track beside the Boyne River at Benaraby at fireman Col ???s place. He still has the Mk2 Matador which aparrently was a hot setup for MX in 1965.
Yes I'm into Sherpa Ts and OSSAs and anything else from the 1970s. For many years I was a Yamaha-only person but gradually developed a burning desire to know what the other bikes of my youth were really like to ride so I set about getting one of each bike that I fancied as a kid. Most are rebuilt from basket cases because that was all I could get hold of at the time. I've kept them all basically standard so other people can give their opinions on a standard bike too, riding them back to back. It might be crazy but I love it. The only serious mods I've done are to lower the pegs on my TY250B and that is because there is a standard TY250A to ride if people want to feel what a standard TY250 feels like - and I've pretty much gone to town on a TY175B - its like a rolling test bed for modifications.
About JCs TY250A, even standard they make a very good Alpina type bike in fact that is one thing I use the TY250A for. The other use for the TY250A is to ride it at trials exhibitions so lots of old dudes like me can tell me how they had one of them as a youngster. The later TY250s had a smaller gap between 3rd and 4th gear but that doesn't stop it being a blast to ride up mountains on.
Firko your TY250A sounds interesting. I was just about to redecorate the TY250B in pearl and metallic green and following the paint patterns on the TY250A because it has looked too standard for too long.
In about 1974 the local trials hotshots where I lived in Brissy had a pre-production TY250 that had been brought to OZ and ridden by Mick Andrews when he was here. I think it had a plated swingarm. Can't remember if the wheels were YZ or not but it had a distinctive exhaust that went straight up from the exhaust port like an OSSA MAR. It had a paint pattern the same as a TY250A but the yellow bits were metallic maroon. If you think that one might be your bike I can put you in contact with the person who owned it back then.
I think the prototype TY250 that Mick rides in the old Yamaha promotional films made near where he lived and that he rode in the 1973 SSDT might have had YZ wheels. Now theres an excuse to look at that film again!
You know if you ride around on that Maico then get on a TY250 it would feel like a feather by comparison, even though the weights are probably very similar. I know that Maicos are endlessly cool, but its enough for me just enjoy looking at them nowadays.
David
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D, Yes I was a tru-blu local. Lived there fron 59 when I was 2 till I went away to Uni in 75 & on/off thro 70's & early 80's.
I sure did race at Boyne Raceway - in fact I designed the track you mention on Col Howse' place (w his son) & on which our club ran the 75 Qld 250 championships - a great day. Col's son & I were school mates & went to Uni together. I was down at his place every 2nd weekend riding/racing that track. If I say so myself, it was a great track.
I rode his Mk2 matador a few times too. They weren't that great tho the previous owner raced it reasonably successfully in local 'scrambles' in 70-71 before he went onto become B grade trials champ in Qld on an Alpina he rode to work. Last I heard Col had quite a collection of bikes.
RE the TY250. I was going to ask you about the placement of the pegs. Just 1 look & they look way too hi - tho the MARs were quite hi too as I recall. No doubt Mick's preference.
I'm thinking of using a DT gearbox & barrel&head in mine, probably w a longer swingarm too. I have the TY gearbox, but don't have TY top end.
I remember the show circuit Demos on the TYs but can't remember the guy's name. Don't think it was Peter Pace (Oz champ at the time) but it was somebody supposedly fairly prominent at the time- ah yes, Dave Pinkerton wasn't it?
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JC
Yes Dave Pinkerton was a legend of that time and another rider from back then is still riding - Steve Johnson. Do you remember the two of them in the movie Naturally Free on their trials bikes doing endless wheelies? Steve still rides trials and his son Brendan is the current Aussie Twinshock champ riding one of Dad's Sherpa Ts. Steve rode pre-65 Classic this year at the Titles and came second.
I've met Cols son but know his daughter Julie much better as she is the wife of a riding buddy (Ian Gudgeon). You are probably the right age to know Wayne Onions, Reg Pugh and Os Blacker too.
The MX track for Gladstone has moved around since then, next being out near ORICA on the way to Mt Larcom next to the mud flats and with a beaut flat-track made from imported deco granite. About 6 years ago we finally had to give up that land for the new Rio Tinto alumina refinery and the current MX track was built at Benaraby in a motorsport complex including the drag strip, on the Western side of the Bruce highway, a bit South of opposite Cols old place.
About the TY, the TY250A motor is probably very close to DT2/3 or DT250A port timing, the main performance difference of the TY comes from having a weight band added to the OD of the flywheel. Later TY250s also have milder port timing that makes them a bit better for trials competition.
Mick wanted the pegs high on the OSSA and the TYs and a few others at the time followed the trend like the Cota 348 and the KT250. The height of the pegs was simply to improve ground clearance. Bultacos never went that way. Mick liked to turn tight with the arch of his outside foot resting on the end of the footpeg so that is one reason why the OSSA and TY pegs are so short. The other is that it reduces the overall width of the bike for better clearance. Bultaco Sherpa T pegs are shorter than Alpina and Pursang pegs (but did not follow the high footpeg trend). If you have bars that are the same (high) rise as what came on TYs new, then the riding position is not too bad, but lowering the pegs does improve balance at rest. Remember that when these bike were made, there was no stopping allowed so continuous forward movement was critical - and balance was not as critical, hence the ground clearance issue. Current rules allow for stopping. Modern bikes are much lower than twinshocks and their footpegs are also as low as possible, to improve stationary balance. Many twinshock riders use modern techniques (stopping and hopping the front) so also benefit from lowering the footpegs. Likewise it is an advantage to have a more upright stance for unweighting the front for hopping it sideways so the lower pegs help here too.
We must be pretty close in age.
Here is a picture of my TY250A from a riding demo at the Rockhampton Heritage Village. Since this demo day with our portable obstacles, we have constructed a permanent trials riding display area with rocks and logs dug into the side of a slope. It is a terrific setup and a great way to publicise trials, especially on the days they run the Heritage Machinery days.
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Firko
I just had a look at the old Yamaha publicity film that shows prototype and pre-prod TY250s and can confirm that the front and rear hubs are both YZ type on the bike he rode in the 1973 SSDT.
There is also footage taken near Micks house of him on an earlier prototype that has hubs that look like AT3/CT3 hubs. On this older bike the flywheel cover lacks the fancy groove pattern seen on the TY250A production item.
David
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Firko, it sounds like you have a rare bike. Resto it and bring it out for a couple of rides.
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Dave, the guys you mentioned were a couple of years older than me. I knew Reg Pugh's younger brothers. Oz Blacker bought the Yam dealership of Dick Burns as I recall but I was long gone from G'stone by then.
Yes, I noticed that the Sherpa Ts never went the hi-pegs route. They were the only trials bike I had anything to do with. I remember riding the 1st model 325 SherpaT (M91/92?) & instantly feeling like I could do anything (trials-like) on it, but never persued competetion trials.
The TY engines are quite a lot diff to the DT. Diff crankcases, diff placement of kickstarter (higher), much larger dia crank (appears same as DT360 except for pin offset for shorter stroke), diff clutch & ign covers, diff primary reduction & much milder port timimg than DT barrels (tho stud spacing is the same), as well as the extra band on the ign flywheel that you mentioned.
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Dave,
Which model later TY's had the diff gear spacing & diff porting?
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The A model is the odd one out for gaps between the gears. I notice it most when trail riding and there is a huge gap I think from third to fourth. The gap is right where you want a gear to be for flowing stuff amongst trees.
I have a B and a D too and they don't seem to have such a big gap as the A. I'll have a look in the parts books later tonight when I've put the kids to bed and see what I can find.
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I couldn't resist looking at the TY250 books.
The books reckon that as far as internal ratios go, the A and B are the same and the C and D are the same, and the only difference is in 4th gear, in that the C and D are a bit faster in 4th. The ratios are:
A and B: 2.714, 2.058, 1.523, 1.000, 0.656
C and D same as A and B apart from 4th which is 1.038
There is a bit of disagreement between the books too. I'm looking at the Yamaha TY250A parts book, the Yamaha TY250A/TY250B parts book, the Yamaha TY250C parts book, the cycleserv TY250B service manual and photocopies of service data sheets for the TY250A and 434 model (our B model) and the TY250C model from what is probably a US multi-bike tune-up data book.
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Dave,
My TY bottom end is #493. I always tho't that made it a B model, but from what yr saying maybe its a C.
Should it have 1.00 4th gear or 1.038?
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493 prefix on the motor means C or D model.
493 prefix on the frame means B, C or D model. The B frame is different to the C and D but they retained the prefix.
434 motor prefix means A or B model.
434 frame prefix means A model.
a 493 prefix motor should have a 1.038 4th gear ratio
The porting on the first of the A models is like the DT3/DT250A. These barrels are visually distinctive in that they have a boss above the exhaust port where a decompressor could be fitted. The later A model barrels and the B model barrel have no boss there. Here is a link to some photos I took a while ago trying to illustrate the differences.
http://www.trials.com.au/phpBB3/viewtopic.php?f=16&t=3938
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Thanks D,
Whats the good oil on the footpeg relocation? Is it worth moving them rearward a little when then moved down?
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Yes they can go back a little bit without upsetting the riding position. Suitable front/rear location of footpegs seems to be in a range from an imaginary line that touches the OD of the rear tyre at the front of the tyre, to about 75mm forward of that point. The further forwards you go the more comfortable it is to ride sitting down and the worse it is standing up for very steep uphills. I'm only 5' 10" so I don't know for sure but I suspect that moving the pegs back even more than that range might benefit a very tall person.
I have a tall riding buddy (maybe 6' 4") who moved the pegs on his Montesa Cota 348 which is a bike with similar high pegs to the TY250 and he lowered the pegs 65mm pretty much vertically and it transformed the ergos for him and the bike almost balances itself. The trade off with pegs that low is that they hit rocks where other bikes cruise over the top. The bottom of his are slightly below the lower frame tubes.
Theres another string in that twinshock trials forum that shows where I put my TY250B footpegs and it made the bike better for balancing stationary and much more comfortable for my feet. The bottom of those pegs is the same height as the bottom of the bashplate.
David
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Thanks D,
I was thinking straight down, but above bot of bash plate.
I scaled off the distance from front axle to pegs on SherpaT, TY & Cota & they all scale at close enough to 950mm, even tho wheelbases are a little diff.
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Firko, it sounds like you have a rare bike. Resto it and bring it out for a couple of rides.
That's the gradual intention but I've got about five projects in front of it on the assembly line and I'll sort my Maico trials bike first. It's a unique piece of Aussie trials history in itself.
I'm a bit exited by the possible Mick Andrews connection and the mention of Dave Pinkerton and Peter Pace. I remember seeing both of those blokes riding over VWs and 44 gallon drums at various country shows back in the seventies. I can't remember what either was riding except for a slight memory of Pinkerton hosting a trials school at Menai with a TY, but I may be wrong on that. I have a sneaky suspicion that the bike is something special so tracing its history is equally as important to the project as is getting it going. I really want to restore it with the green/white paint scheme so if any of you have any photos of early trials showground performers, even if they're in black and white I may be able to tell if it's the bike or not.
I won't be getting down to the farm until New Years Eve (for our annual New Years Eve party). When I'm there I'll drag it out and snap off a couple of shots of it. It's been locked in the shed (an old shipping container) for so long I can't remember what other goodies are in there with it. Possibly TL 125 and SL 125 Hondas and a DT400B. It's got my curiosity up now.
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Firko, Kevin Brown knows a guy called Howard who rode a lot of trials back in the 70s, he might be able to help you with the TY. Howard was the guy that rode a Honda wheelstanding down the aisle of a office between the desks in a Honda advert.
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I remember that ad! I'd like to have a chat with Brownie but I won't do anything until I get some photos of the TY. Ta Pete.
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I just remembered the guy's last name it was Howard Chapman. Must have had to many Kozels last night ;D ;D ;D
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D,
Despite several searches I can't find the thread on the trials forum about the relocation of TY footpegs. Any chance you can point me in the right direction pls?
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It was quite a few topics down from the top
Here it is
http://www.trials.com.au/phpBB3/viewtopic.php?f=16&t=2678
David
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David,
Is there any advantage to lowering the pegs on the TY250? I am after as much ground clearance as I can get. I've see it done to the ty175. Would it be better to locate them further back, not lower? As I'm trying to get my bike ready for the '09 season, any help is needed.
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Thanks David (for the site reference)
Did you make yr own footpeg holders/brackets, or adapt something off another bike?
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Oldbiker, they feel great for balance just a bit lower than standard and I don't feel cramped up in turns and the front is light enough already so haven't wanted to move them backwards. Since I did that mod in the photos on the TY250B it has probably done 10 trials and don't remember any issues with the footpegs hitting anything, so for me they are probably still high enough. I've found that main problem with ground clearance on the TY250 is under the motor as it is among the lowest of the twinshocks.
JC, I made the triangular 5mm steel plates. The U shaped brackets welded to them are from a Sammy Miller Products Universal footpeg kit, which is what I first used on the TY250B. Those footpegs then went onto my Majesty. I had the HEBO footpegs lying around so they went on the TY250B. Most modern trials footpegs fit those same U shaped brackets. The top mounting point for the 5mm plates is the frame lug left after you cut off the standard footpeg mounts. The bottom mounts use existing threaded holes in the frame cross tube (if your TY250 is a B model or later).
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Feetup, I have a '74 TY250a. I don't remember the threaded holes near the pegs. Which later model pegs fit the brackets?
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To use the same idea for the brackets but on a TY250A, weld a disc of 6-8mm thickness in place of your TY250A frame tube cap and drill and tap a thread into it.
As far as other pegs go that fit standard TY250 mounts, I've never come across any. Most people just extend the standard TY pegs. I think there is a photo showing that idea posted in that same Trials Australia thread I put a link to above.
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ok I'll try the link and find the pic. I might pinch the welder off the neighbour and extend the pegs..