Author Topic: RD350 Dirt Tracker  (Read 84919 times)

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Offline frostype400

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Re: RD350 Dirt Tracker
« Reply #30 on: April 23, 2013, 09:47:42 pm »
Pete do you still have the grab rail don't know if it is the same but looks as though it might be mine on my 76 rd250 is broken I doubt you will run the same tank as mine I am doing it as original and it has the coffin tank and dg pipes. :)
1971 tm400 and PE's

Offline yamaico

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Re: RD350 Dirt Tracker
« Reply #31 on: April 23, 2013, 10:03:52 pm »
Hi Michael,
I still have the grab rail and the tank. The grab rail has a bit of surface rust but the tank doesn't look too bad. The pipes are very rusty so not much use but you're welcome to whatever you want. You should be able to cross reference the parts numbers but I would assume they would be the same.
Pete.

Offline frostype400

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Re: RD350 Dirt Tracker
« Reply #32 on: April 23, 2013, 10:14:55 pm »
Thanks Pete that is ok I think I can just oxy weld my rail it is only in one spot but thanks for offering and the tank I have sorted here is a pic.

Is the front rim off the bike salvagable as mind has a massive flat spot I sourced one other but it was slightly different.






Cant see the flat spot in this shot but it is a decent on this is not long after I got the bike.


1971 tm400 and PE's

Offline frostype400

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Re: RD350 Dirt Tracker
« Reply #33 on: April 23, 2013, 10:17:51 pm »
I just found this pick other side looks like the rail is different after all sorry for the hijack.

1971 tm400 and PE's

Offline SON

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Re: RD350 Dirt Tracker
« Reply #34 on: April 23, 2013, 10:34:04 pm »
are rd400's allowed in the twin dirt track class?who sell that digital spirit level and was the bending of the frame tubes done cold or with the aid of a oxy torch?
Yes certainly are
We might end up with handicap races to balance things

Offline TT5 Matt

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Re: RD350 Dirt Tracker
« Reply #35 on: April 24, 2013, 02:07:11 am »
ok Pete and Son ill watch Petes bike like a lot of others here with much interest!!theres a rd400 at the wreckers ill have a look at soon and see how good or bad it is,hopefully the motor is in good nick as that's where the big bucks go if its not up to it ;) ;D

Offline Sorelegs11

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Re: RD350 Dirt Tracker
« Reply #36 on: April 24, 2013, 08:08:25 am »
Just received a free t20-67 complete just been sitting under a tarp for 30yrs, am I giving it away at $500.

Good to see an RD in progress!
If at first you don't succeed, lower your standards.

Offline pancho

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Re: RD350 Dirt Tracker
« Reply #37 on: April 24, 2013, 11:04:11 am »
 Hurry all your entries to Nepean Syd. West round two with these!
 I want to see them go!
cheers pancho.
dont follow me i'm probably off line!

Offline yamaico

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Re: RD350 Dirt Tracker
« Reply #38 on: April 30, 2013, 10:50:18 pm »
Got started on the swingarm. Cut the shaft out of the old RD one and started to make a new one with some 50x25 rhs. It's a little bigger than I wanted to use but was easy to source and is the same size as a DR250, so should be OK. I still have to cut the axle slots in and make a brace for the front but I'll wait until I work out the exact length before I weld it all together as I have some decisions to make on the front end.

 

I have some old 250 Kawasaki road bike front forks that are 36mm and in perfect condition. I also have some 36mm IT forks that are in poor condition but have good sliders, but they are leading axle. Their associated triple clamps have very little offset as opposed to the RD ones that have a lot of offset. I took some measurements of the frame and the triples so I need to draw it all up with the 25 degrees of rake and see what combination gives me around 100mm of trail. If I end up using the RD clamps I'll need to bore them out from 34 to 36mm. Once that's decided I can go ahead and finish the swingarm to get me to the 55-56" wheelbase that I'd like.





Just as an aside I weighed the two back wheels and there is over 6kgs difference.
 


Shouldn't be too hard to shave a fair bit of weight off this old lump.;D

Offline yamaico

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Re: RD350 Dirt Tracker
« Reply #39 on: May 08, 2013, 06:52:50 pm »
Checked all my triple trees and found an old set of Yamaha ones that, in my opinion, had the best combination of offset and trail for the 25 degrees of rake that the bike now has. They were only for 34mm forks so made up a quick boring bar to take them out to the 36mm required for the Kawasaki forks.



As I don't have my mill set up yet I had to use a little drill press that I have. Found a bit of plate to bolt the trees to which was then bolted to the drill press bed. The mandrel on the boring bar is exactly 34mm which enabled fairly accurate alignment of the triple tree to the boring bar. Did a test run on the lathe to set the key steel in exactly the right place to bore to 36mm, which was very fiddly and took ages.



Bored the first one and it went well until the guide mandrel came through the bottom and it started to chatter a bit.



Quickly made up another mandrel at a shade under 36mm which stopped the chattering at the bottom.



Finished all four holes which all came out quite well. Bead blasted the top tree ready for powdercoating but the bottom one must be in two pack as the bead blaster wouldn't touch it. Will have to get some paint stripper on to that. ???



Have to fit the forks up into the frame then work out how much they will need to be shortened. Can't drop them through much as the bars are across the top of the fork tubes. Also have to weld a lug onto the lower left hand leg for the front brake plate lug.

Offline tony27

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Re: RD350 Dirt Tracker
« Reply #40 on: May 09, 2013, 03:14:43 pm »
When you mentioned the chatter as the support disappeared I was thinking do I mention making an upper sized support, then I saw the next photo & comment.
Very nicely done, will be keeping a watch on this thread

Offline TT5 Matt

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Re: RD350 Dirt Tracker
« Reply #41 on: May 09, 2013, 07:56:52 pm »
keep these home brew special tools coming Pete. like tony27 I was thinking the same about a top support,proberly not a problem on a milling machine but drill presses arnt as tight in that area.as to the rd400 but was at the wreckers that's gone and he cant remember who brought or even when it was sold ???

Offline yamaico

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Re: RD350 Dirt Tracker
« Reply #42 on: May 09, 2013, 10:20:57 pm »
as to the rd400 but was at the wreckers that's gone and he cant remember who brought or even when it was sold ???
Keep looking Matt - should be plenty of them out there...

Offline firko

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Re: RD350 Dirt Tracker
« Reply #43 on: May 09, 2013, 10:25:22 pm »
There was an LC roughy on eBay recently....not sure how they'd go modded for dirt track though.
'68 Yamaha DT1 enduro, '69 Yamaha 'DT1 from Hell' '69 DT1'Dunger from Hell, '69 Cheney Yamaha 360, 70 Maico 350 (2 off), '68 Hindall Ducati 250, Hindall RT2MX, Hindall YZ250a , Cycle Factory RT2MX flat tracker, Yamaha 1T250J, Maico 250 trials, '71, Boyd and Stellings TM400, Shell OW72,750 Yamaha

Offline TT5 Matt

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Re: RD350 Dirt Tracker
« Reply #44 on: May 10, 2013, 01:36:28 am »
sooner air cooled,hate getting coolant on my hands.besides that its more things to go wrong and lets face it its only 3 or 4 lap races.bike u mentioned I couldn't find it anyway