jc2

Gents, there seems to be a few 'wires crossed' in this thread. Dalesman may have produced a Hodaka-engined bike - I don't know - but the bike pictured is definitely a Sprite (Avenger, as mentioned by Scot Taco).

Many thanks fourex. cheers

Does anyone know the ID & OD of the steering head bearings for the 350T with Betor forks?

The other thing to consider is that as the actuator cam gets closer to 90deg, the amount each shoe is forced out into the hub gets closer to being the same for both shoes, potentially bringing the second shoe more into play for increased braking effect. That's not to say that I'm suggesting it should be run close to 90deg, for the reasons given above. It's always a trade-off, a compromise with pros & cons each way.

Hmm, yes you may have nailed it westyfield; frame & swingarm do look remarkably similar

One magazine article said the 3 man '68 SSDT team had one red, one blue & one bronze bike. The following thread mentions several colours: http://www.trialscentral.com/forums/topic/47920-gaunt-suzuki/?hl=%2Bgaunt+%2Bsuzuki But remember that Alta-Suzukis, Taylor-Suzukis & McLaren-Suzukis are often confused with the Gaunt-Suzukis & assumed to be the latter. If you google-images B100P/B105P (bearcat) you'll see most of the original models came in black or red but there were some green and some blue also.

My M27 is stamped on the steering head too, but there was a third spot where some early Bul frames were stamped - I think it was under the seat somewhere.

Bit of a mystery but I think trialsrfun is on the right track. Tank-seat looks like Dalesman enduro, forks??, frame looks very Cotton-ish except for swingarm which looks Rickman-ish or AJS. Never seen chain adjustment at swingarm pivot on a Cotton tho. Wheels/hubs Japanese? Perhaps a modified/bitza Cotton Trials Starmaker? As far as I know Saracen never made a Villiers engined bike. Looks very interesting tho.

Here's one built in Australia many years ago. The chap on the right won a state Classic title on it in Queensland in 1990. Uses C11 piston to take it to 220cc

You may find that your Matador does not have the usual wide ratios typically specified for Matadors/Alpinas/Lobito/Fronteras etc. I had one early Matador engine that had much closer ratios from another model.

There is another reason said to be the reason that single leading shoe brakes work better one direction than the other. If you think of the mechanics/physics of it, the inner lobe of the actuating cam pushes that shoe out further to the hub/brake surface than the outer lobe does (because the inner lobe is closer to the pivot point of the shoes). So if that shoe acted upon by the inner lobe is the leading shoe the brake is thought to work better than if it is the other way round. Switching which side of the bike the brakeplate is on also changes which shoe is the leading shoe (if the actuator & cable set-up on the brakeplate remains the same when you switch) so you get a more favourable outcome on one side compared to the other.... at least in theory. On the MAR the more favourable set-up is the way you now have it with brakeplate on left.

Charlie, I can only say that there may be a 2nd Otter in Oz. I don't know for sure. I'll see if I can get some info on the one I know of for you. cheers

Charlie, I've checked with the owner of this one is OZ that I know of & it's not a Foster Otter. This one uses an early Howard Fawkes frame. There may be another Otter here that I don't know of tho. It's a huge country!

There is indeed an Otter in Oz (Australia), only a couple of hours drive from me. B40 engined. Looks stunning! But I don't know if its a Harry Foster one.

The Cota 247s don't seem fashionable in twinshock trials but it's about time I got mine (a Mk4) running so can people who are using them tell me what sprockets/gearing they're using? cheers.

Anyone got any pics of the M27?

The guys are correct saying too much trail. Honda trail/enduro bikes of the era using 21" front wheel typically had 51mm total offset between axle & steering axis. A TY twinshock has 70-72mm. Its this offset, causing trail, that gives the self-steering effect, ie when you lean, it steers into the corner. However the amount of offset you need for that effect is very different at slow speed to that for high speed. What works for hi speed feels very floppy at lowspeed, ie it wants to flop into the turn too far with just a little lean. And conversely what is good for low speed feels very twitchy/unstable at hi speed. Its always a compromise Using other 35mm fork sliders without offset axle in those same Honda triples will make the floppy steering infinitely worse.There's really nothing you can do with those Hon forks/triples that will make it work, short of reducing rake to about 22deg! (which of course will stuff others things - wheelbase, weight distribution etc). Or getting the triples machined to 'kick out' the forks a couple of degrees, thereby increasing axle offset & reducing trail. I'd be taking up your option of fitting the TY250 triples & forks. That'll cure it. Or if you still have your Ty175 triples they can be reamed out to take the 34mm TY250 forks. (Same triples) Another option is TL250 forks & triples but they are longer than TY forks so you'll have to compensate. They're 33mm tubes. Probably simpler to stick with TY ones. There is a good thread on understanding steering for trials here. http://www.trials.com.au/forum/viewtopic.php?f=16&t=9348 It basically summarizes what the gurus (eg Tony Foale) said in print, after much experimentation, & applies it to twinshock trials. (Just to complicate matters, trail also caues the self-centering effect which is dealt with early in the thread. The self-steering effect is dealt with at top of pg2)

I think you'll find that Tom Ollerton was entered on a SherpaS based 175/200 in '62 & '63 & I believe again in '64. And Oriel Puig Bulto was entered in '64 on a 200, either an M3 or M4 based prototype. It's well documented in the public domain. But as revealed convincingly on TC recently not even Miller rode an M10 in '64: 669-NHO was a modified M4 - http://www.trialscentral.com/forums/topic/57725-discovered-sammy-millers-original-bultaco-sherpa-669nho/ Allowing the M10 surely makes an open mockery of the Pre65 cut-off date, but then, as others have often said, that's already been done by many/most of the 'fiddle' bikes. It again begs the question, as Roger said above: Why haven't they dropped the farcical "pre65" moniker & called it something else more fitting? Perhaps the organisers in their wisdom, & in the light of other 'fiddle' bikes already allowed, have deemed the M10 to be little/no different to or better than an M3/M4 etc !!? No doubt that the particular M10 mentioned above (which has been entered) is "an unmolested original motorcycle" ... "which is more than can be said for many of the so called Pre65 bikes out there". But is that really the point at issue here? This is the one event that affects classic trials almost everywhere so the repercussions will most likely reverberate around the world. And some of those repercussions, when followed thro to their logical conclusion (which they will be), are potentially huge. Can't help wondering how long it will be before there's a 4sp Bultaco 'replica' lightweight frame available with modern geometry. Then will the floodgates open & history repeat itself? As someone famous said, "The only thing that man has learnt from history is that man doesn't learn from history". Trouble is, it seems that we still haven't learnt that lesson. PS I hasten to add that I say all the above as a Bultaco man, not as a Bultaco hater

Traf, I'm no Villiers 197 expert but you don't seem to be getting much help here so having looked into the potential of the 197 Villiers a bit myself lately here's a few tho'ts: If you are familiar with Roy Bacon's book the 8e & 9e engines are listed with the same C.R. (7.25:1), same port durations (In 134deg, Ex 152deg, Trans 126deg) & same power (8.4hp @ 4000rpm). The 7e "competition engine" does not have durations listed unfortunately, but the CR (8.25) & power (9.3hp @ 4300rpm) listed for it are the same as listed as a competition option for the 9e so I'd guess that all the cylinders had the same porting (7e, 8e & 9e); they just raised compression on the 7e (& 9e option). The 7e was said to be developed for trials with available piston options from 8.25:1 to 10:1 (see http://www.users.globalnet.co.uk/~pattle/nacc/arc0596.htm) but Bacon said the 7e had a different hi comp head so it may have been a combination of both diff head & piston to raise CR. Taking 1mm off the top of the cylinder raises the CR by approx 0.9 on the 197 engine, ie from 7.25:1 to 8.15:1 on an 8e (if the head & piston remain standard) which still isn't quite as high as the 7e competition engine. Regarding Inlet duration, Bacon lists it for the 37a as 140deg so the suggestion to increase the 8e to that looks plausible You'd think that boring the cylinder to take the 1H piston would be a useful mod too with noticeable benefit, raising capacity as it does by 14%. But... the standard 197 Villiers porting looks to me like it already 'strangles' the engine. Apart from the physical size limitations of the ports there seems to be an issue with limited blowdown too, leading me to wonder if they could also benefit from a little raising of the exhaust port (& widening if it's not already at the limit for the rings) amongst other things. Then I found this guy's experience which is more-than-a-little relevant. He got some good advice leading to what appears to be a good outcome: http://fboc.niceboards.org/t2952-more-power-please Useful pics too. The top-hat shaped combustion chamber is interesting. I'd have tho't they could do with more of a squish band. Either way it looks like there's a fair bit to be gained in the head. Also, have you seen the Villiers Singles Improvement Handbook? Tho it has a fair bit that's more applicable to roadracing, you may find it useful. There are excerpts/samples from each chapter on the website at villiers.info Edit: I corrected the link above for the handbook.

Fantastic news.That makes a lot of sense. Someone asserted on this forum before that SHM's original 669NHO was an M4 not an M10. Does anybody else notice in the article how much lower the front of the engine sits in that frame compared to a prod'n M10? The engine is tilted noticeably downwards at the front.

I have edited my 1st post & added a pic of the more common hub (bottom pic). Notice the groove around the outside of the brake liner that the top one does not have. The top hub has 122.600M cast in. The bottom one has 122.600BM I managed to find ossa parts diags on the net - thanks ossaworld - & 72MAR has 122.600M whereas later MAR has 122.600BM. Diff brake plate for each, as you would expect from above pics, so mystery solved I think.

Gents, can anyone recognize this Ossa front hub in the top pic? 122mm dia. Please note that there is no groove around the outside the brake liner. (Other 122mm Ossa super pioneer hubs I have have such a groove - as in bottom pic) Perhaps a Mk1 MAR ?? cheers

Is this a typo or did the M16 Matador use an M4 engine prefix rather than M16 ??

Johnny, if you read page 1, from post #4 onwards I think you'll find your answer

Love it. Wish I had the skills