OzVMX Forum
Clubroom => Competition => Topic started by: mboddy on April 15, 2008, 07:15:11 am
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I had a great day at Heaven Round 2 in Canberra on the weekend.
My first MX meeting in 30 years!
It showed up a few things that I need to sort out with the bike.
The front brake was really bad.
I noticed the YZ250C was using a Yamaha twin leading shoe front brake.
I haven't been able to find any evidence that this was available pre 1978.
Are Yamaha twin leading shoe front brakes Pre78 eligible?
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Are Yamaha twin leading shoe front brakes Pre78 eligible?
I wasn't aware they were Pre 80 legal.
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It showed up a few things that I need to sort out with the bike.
The front brake was really bad.
The Yammy brake was renowned as the best of the period so if you were noticeably down on brakes either
1/ you're forgotten how to brake in the dirt ::),
2/ your brake wasn't set up correctly in some regard ;), or
3/ you're just riding too fast ;D.
I'm no expert but I don't think t.l.s. brakes appeared on production mx'ers until about '82.
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In a word...No. I agree with Graeme that the Yamaha brake is the best in the business. I'd be checking my cable to test if it's stretching , and looking for soft compound modern brake shoes. Are your shoes the originals? Are you used to riding a disc braked modern bike and are expecting similar stopping power from your old YZ?
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The cable is stuffed. The hub is oversize.
I have a new cable coming as well as a very good hub.
I just wanted to make sure that when I have finished I had the best front brake that was eligible.
Thanks, Mark.
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Since the question was asked, when was the first t.l.s. MX brake released on a production bike? And what make model?
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Pretty sure the first Yamaha was YZ465H (81), but I could be wrong. I think they went on the 250's as well in 82.
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If you do all of the tricks to the IT hub, and are still unhappy, then there's also the XT500/DT400 front hub/brake to use.
Same style of conical hub, but significantly larger in diameter (sorry, can't remember the measurement).
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Honda released the 1975 SL175 street scrambler with TLS, mx no but they could have been adapted back then although dont know if was ever done ::)
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Montesas had them in the mid 60s. Check out the La Cross in my piece in the current VMX.
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The tls first appeared in the 1920s-designed by an aviation engineer and very soon after found there way onto road bikes.I have a picture of a 4 leading shoe(Full width hub) on the front of the Factory 350 Benelli in a 1939 GP. Heat was a problem and venting was essential to delay fade.
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For a little while I ran a Suzuki GT750 4 leading shoe on the outfit, way too heavy and F***all braking when dry, heaps less when wet, replaced it with an SL350 Twin leader .. Much lighter and same braking performance.... So if you rocked up with a steel rim 19 inch SL350 up front there is your legal twin leader...... :D Check out your Yammies brake it should be very nice!
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the '69/'70 TS250 Suzuki was the first from the jap manufacturer to run twin leaders on production dirt bikes ;)
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At the 2nd (and last?) Castrol 6 hour at Nepean I run a yds5 hub, t.l.s. brake, hooked up to a 19in rim. We did it primarily because the small brake faded to zero brakes at the 90 degree left after about an hour.
When was the 2nd Castrol 6 hour at Nepean ? '76/'77? Would this arrangement be pre '78 legal?
Mind you, Bobby Mayes of Willoughby club was running a CB750 disc on his Maico in about '74.
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if the disk was available pre78 its OK as is a TLS drum, where you come unstuck is when you use a later item and try and get it passed. None of its a problem when you consider the period and work within it.
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