seth29

First mono shck trialsbike

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As the a/c mon shock forum has gone a bit shall i say boring am hoping this will spark off some fun.. what was the first mono shock trials bike, not a ridgid, was it the legendary ty 250 mono or the JCM 323 or was there other pre production bikes. What year did the ty mono did development I know pre 1984 as one N Berkett was a develepment rider but in 1983 was on a jcm so was the ty all done and off to the next challenge??? we are talking months days not to sure what do you lot think.pretty sure 1984 was the year....I have 323 that was made on the 17th aug 1983 that i think is the first production bike...as th ssdt was the challeng for a bike what was there???

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I believe yamaha had several mono shock ty`s. Most 77 -80. Not production available to the public, but had been visable for all to see. The ty250/350 had to be the best bike made in the 80`s.

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1974 was the first well-known Yamaha single-shock trials bike. It was a Tilkens (non-linkage) design rear end like the early YZ and MX Yamahas. Mick Andrews rode the SSDT on it that year.

The first Yamaha linkage-type single shock trials bikes were in existance in the early 1980s as development bikes but the design was not "revealed" until 1983.

There were probably home-made single shock trials bikes before Yamaha started making them.

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Probably a Vincent Comet as I'm sure somebody must have used one in a trial.

Certainly the Cheney Ossa were around the same time and may be slightly earlier than the Yam cantilever.

I would be interested to know the exact date they were announced if anyone has some old MCN's.

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Probably a Vincent Comet as I'm sure somebody must have used one in a trial.

Certainly the Cheney Ossa were around the same time and may be slightly earlier than the Yam cantilever.

I would be interested to know the exact date they were announced if anyone has some old MCN's.

Think the Vincent was cantilever, but had 2 shocks side by side to save space.

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As the a/c mon shock forum has gone a bit shall i say boring am hoping this will spark off some fun.. what was the first mono shock trials bike, not a ridgid, was it the legendary ty 250 mono or the JCM 323 or was there other pre production bikes. What year did the ty mono did development I know pre 1984 as one N Berkett was a develepment rider but in 1983 was on a jcm so was the ty all done and off to the next challenge??? we are talking months days not to sure what do you lot think.pretty sure 1984 was the year....I have 323 that was made on the 17th aug 1983 that i think is the first production bike...as th ssdt was the challeng for a bike what was there???

Seth your confusing two or three different types of JCM.

The 323 was a Tau engine as riddden by Charles Coutard, Joel Descuns, Benard Cordonnier and John Reynolds. This bike was tested by Birks for TMX but he never rode one other than that as he was on the Yam at the time which was light years ahead. There was also a 250cc version of this bike. This is the original JCM factory, their last bike had the tank under the seat and its best result was 3rd in the 86 French WTC tround in the hands of Pascal Cotourier. As a mono it as first ridden by Coutard and Descuns in the world rounds in 83, Descuns rode the SSDT in 84 on one.

None of these models were imported prior to June / July 1984, your bike will have been made in 83 but at that point there was no importer so its either been brought into the country by an individual or its been old stock when supplied by JCM.

This JCM concern went bust late 86 / early 87 but a new JCM company was launched and Tony Scarlett signed for them and rode that bike, called a Viga for two years, this was similar to the last bike Cotourier had but with a Gas Gas air cooled engine which I think was based on Moto Villa MX bike.

The next JCM incarnation was the Striet JCM, this was the bike ridden by Birks and imported by Bob Gollner and I suspect was another different company from the one Scarlett rode for.

JCM had their bike out in public in the WTC in 83, Bikrs first rode the Yam competitively in Aug 83 I think at the Hillsborough as it was then. The Beta TR32 came out early in 84 but again wasnt as good as the Yam.

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your bang on my bike is one of the first 39 made by Joel Correy. it was a French rider that first got his hands on it, then sold it in England. its not like the 323 of 1984 it will only start out of gear and had the rear damper that lost air if you sat on the bike. as for fork angle could be a Harly Davidson but after money that could have got a new gas gas its ok but still won't turn as i want.

I found a tmx on e bay some time ago with birk on a 323 but just presumed he was riding for them not that it was a test.

So back to the start, what was the first production bike that a man could buy was it the beta,yam or jcm. went over to see Joel Correy and he showed me a pic of a jcm in the ssdt in 1982 but this was a pre production bike so not counted.

seth..

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Probably a Vincent Comet as I'm sure somebody must have used one in a trial.

Thrasher Grunge?

Micks the man

I wonder if Mick got dizzy?

Edited by TooFastTim

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Think the Vincent was cantilever, but had 2 shocks side by side to save space.

Indeed so but barred from Twinshock motocross apparently (they can't be scared they would thrash a CZ surely) despite pictorial evidence that they were raced in the day. There's a famous picture of Lindsay King doing a nose landing on a 1000, brave man, in, I think, a Vincent history.

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Indeed so but barred from Twinshock motocross apparently (they can't be scared they would thrash a CZ surely) despite pictorial evidence that they were raced in the day. There's a famous picture of Lindsay King doing a nose landing on a 1000, brave man, in, I think, a Vincent history.

The Vincent has only one shock absorber-the two "shocks" referred to are actually spring boxes,containing just springs. The single shock absorber is a seperate unit fitted centrally,with a spring box either side.

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The Vincent has only one shock absorber-the two "shocks" referred to are actually spring boxes,containing just springs. The single shock absorber is a seperate unit fitted centrally,with a spring box either side.

True enough.

There is a body of opinion that considers shock absorber to be the correct term for the normal combined spring and damper unit, and I'm sure some Vincents have been modded to such a (non-standard)set up with two of these, usually Koni if I recall.

Personally I never use the term shock absorber (which was always more of a car term), suspension units being the motorcyle common usage for the damper and spring assembly back in my day. The American "Cycle" felt that the spring was actually what absorbed the shock (with some justification for, as they said, without a spring the hydraulic damper would absorb nothing) and the damper merely controlled the motion of the spring. This would appear to have some logic as, going further back, nobody ever referred to a friction damper as a shock absorber.

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