jc2

Hi all, Can somebody measure for me the correct port heights for a standard 156cc cylinder from the 200 Fantic please? (from the top of the cylinder) Thanks

The Husky in the original post was built from an RT360 - probably the worst bike Husky ever made, but at least it had a very torquey engine. It consists of little more than jacked up rear-end, rearset pegs & lower gearing. Bike is well built but enormously tall, more-than-a-little heavy &... well, you can see the limitations. Maico has had new gears cut but is still ony a 4speed. Frame mods are done very poorly IMO. Current owner did not do the mods. Even more limitations than the husky

Are they 247 Cota forks & triples?

Woody, Are they Grimeca hubs both ends on that MAR you rode, pictured above? Also, has anybody got a pic of Micks bike?

Thats the one, & it is Miller frame, # SM 294

Does anyone know anything about the early development Suzuki prototypes of Gordon Farley? Or have any pics? There's one pic each in Don Morley's "Spanish Trials Bikes" & one of John Hulme's volumes of "20yrs of Twinshock Trials" & a couple more with a little info in another magazine on trials, but not much. Of the few pics there, most look like modified TS250 engine & prototype RL chassis, but one looks like its a SherpaT rolling chassis w RL engine & tank (said to be in 74). Its certainly a Bul front end. Also, an interesting bike has turned up in Canada: a Suzuki engined SherpaT (maybe Miller frame) with the interesting engine # TS-T-00001 Is Gordon still alive? Anybody know him? Anybody got any more of the story or other pics of the bikes?

I tho't John Cane was already offering that kit - with 71mm piston (= 198cc) & porting developed by Reg May back in the day. Worth remembering that some people have reported a problem w the kickstarter breaking when you go for the big-bore kits.

Hi Guys, just found this interesting thread. In response to TrialsRfun's post #88 asking where the frame nos are: (I tried to PM him but it failed) I don't know about the 60's trials frames, but the 70s MX frames that made it to Oz have the numbers stamped upright (not sideways) on the front of the steering head, running downwards under each other. (By the mid 70s they were 4 digit numbers - well on the way to being 5 digit) However, some are stamped very lightly so its easy to miss them, especially if under 2-3 coats of paint. But, several frames have no evidence of any numbers at all & no evidence of them having been ground off. Love to see more pics of the early Trials bikes

I think you'll find Feetup's swingarm is lengthened 45mm not 75mm

Has anyone investigated if any V-Force reed valves will fit the twinshock TY250? (with or without modification)

Hi, Can anyone tell me the wheelbase, ground clearance & seat height specs for Cota 200 please? thanks

Yeh I know Dave, but they don't seem to have everything listed. I've read in a couple of places (what seems like ages ago) that they were about to have em for sale. I assumed/hoped, perhaps wrongly, that they must have been out there by now. (And as you know, a phone call from down under aint cheap.) In the pics I've seen of the TYtrials 175 in CDB & YOU HAVE USED WORDS OR A PHRASE WHICH ARE NOT PERMITTED ON THIS WEBSITE. PLEASE DELETE YOUR POST/TOPIC. DO NOT TRY TO CIRCUMVENT THE FILTERS IN PLACE ON THIS WEBSITE the pegs look lower than the SM ones (which don't seem much diff to std). Does anybody know if/when they'll be available (if not already)?

Is anyone using the TY-Trials footpeg lowering kits for either TY175 or TY250? How do they compare with the SM ones?

Can any Monty experts tell me if there's any tricks to removing the swingarm's pivot sleeeve (on a late 247)? The swingarm is out of the frame & the pivot shaft/bolt is also out. But when I try to remove the sleeve, which presumably should just slide out of the bushes, it wants to 'pick up' the bush & push it thro the other side (whatever side I try) & basically just seizes up. Has anyone had a similar problem & resolved it? Am I missing some basic 'trick'? Or is it just a case of using more force?

JMcK, I don't know what you are looking at. We are not talking about adjustable triples. We're talking about triples where the bottom one has more offset than the top one so the forktubes are kicked out about 1.5deg more than the steering stem. Most 70s twinshock trials bikes had it, including the TYs & SherpaTs.

2 Questions: How far can you safely bore a TY175 (beyong 68mm) without resleeving? Does anybody know what size bore the Majesty website 200 kit uses?

That would be true to some extent, but its not dependant on runout in the yokes. The rising/lowering of the steering head is a result of both/either rake & offset. Thinking of best/worst-case scenario, if you have zero rake you'd have no rising/lowering of the steering head. But there would be no diff whether the offset is obtained with raked out yokes or in the triples/sliders. One would think that the sideways movement in the steering head (which is more a function of offset/trail) would upset balance more than the rise/fall of the steering head, which already changes with suspension/surface undulations.

Agreed. But the runout is usually only about 1.5deg. If that were the main reason its used, they'd surely use nearly straight-across triples w offset-axle sliders &/or considerable runout in the triples.

Yeh Dave, that was the "exception" I referred to above. Its just elaborating the general with some specifics.

Thanks guys but it hasn't really got to the bottom of it. I understand all yr saying, Feetup, but w one exception all those things can be achieved with offset-axle forks/sliders which have the same total offset/trail, & as you know, many bikes have both offset axle sliders & non-parallel triples, eg, SherpaT, KT, RL, Cota etc. So there must be some other reason why manufacturers use it, which I suspect is the main reason. TrilasRfun, thats the sort of thing I've heard/read claimed before, but I don't see how & I've never seen it adequately explained despite having searched fairly widely. eg Foale & Willoughby say very little in their classic book on frame design (which has considerable content on steering). I can see what yr saying that the forklegs are not vert or backwards at full lock with runout yokes, but don't see that that makes any diff for the better. Steering geometry is a function of steering axis angle (ie rake) & total offset - however that total offset is achieved. The angle of the forklegs doesn't provide rake. It all gets a bit confusing (to me at least) on tight turning, but in the worst case scenario, on full lock, assuming the bike itself remains verticle, the rake becomes camber on the front wheel & there is no rake, & with any offset at all (however it is achieved), we actually have negative trail. Seems to me thats why any bike feels much less stable the closer you get to full lock, and with runout on the yokes it makes for more negative trail & therefore a worse scenario! (it seems to me) In fact, its usually improved/cured by providing more (+ve) trail. The only advantage I can see of runout on the yokes is that as the front suspension compresses, you lose less trail than with parallel triples. ie you don't lose as much of the centring effect so the bike is more stable under suspension compression than with parallel triples. But perhaps I've got it all wrong.

Most twinshock trials bikes have non-parrellel triple clamps, with the forks kicked out about 1.5degrees more than the steering stem rake. Can anybody tell me what the advantage is of this set-up (over parrallel triples)? I've read that they're supposed to be better at/near full-lock, but I don't know if thats correct or why/why-not. Can anyone enlighten us?

TY 250 rear hub is same as TY175, but uses sproket with diff offset (& probably diff # of teeth) Are TYoffroad building the stroker kit now or still developing it?

There are 4 different sets of crankcases, each with diff engine mounts & diff non-interchangeable clutch covers: 1) DT1/2/3, YZ A/B, 2) DT A/B (& perhaps C) 3) TY 4) DT D etc (eng mounts are close to DT A/B but slightly diff DT A/B/C/D cases are about 1" longer than TY cases, so its not a straight forward engine transplant, but I did read of somebody (foolishly, IMHO) putting a DT400 engine in a TY in USA (where else?) I think. TY stud spacing on barrel & head is same as DT250 A/B/C/D, & interchange, but diff porting, Comp Ratio Some internal cluth/primary gear/g'box parts exchange, but not all. IIRC TY A & DT A use keyed primary gear; B/C/D models for ea use splines (or vice versa) DT C/D gears were diff (wider) to DT A/B IIRC but not sure if the whole set will interchange. Don't know if shifting forks & drums are diff/same

Anyone know how close the new MATY frames are to production? When they might be available?

Does anybody have the specs for the standard Mini Majesty? eg Wheelbase, Ground clearence, seat height etc