mattylad

Cantilever Ossa were in use by the factory team from about 1974

I ride a fair bit around Europe (belgium, france, germany, switzerland) and most of the expert routes require a degree of modern riding techniques even if they are technically non stop. The "dynamic stop" seems to be acceptable before a big step or drop off to compose yourself. Technically its a five but we seem to be able to get away with it. What I was trying to convey was the fact that the bulto was being used when tyres were rock hard and finding grip was at a premium. Nowadays that is not the case with modern tyres being light years ahead. This means the engine characteristics which were good for the time are not necessarily the best now. I generally ride a Yamaha with a clutch as good as a modern bike on tight turns this is definately a positive atribute as I can crawl round slower than if using a "wooly" engine with the clutch fully engaged. A lot of your riding style depends on your experience prior to going (back in my case) to twinshocks for me I rode modern trials and thats how I feel the most comfortable. I could not ride a bike without having my index finger on the clutch as it would be just as alien as when I started riding with a finger on the clutch 25 years ago. I'm sure I could adapt but that would make it more difficult to ride.

I remember Graham jarvis and Rob Crawford getting stuck on a log at Houghton Towers. God I've never been so board in my life but the comments were funny.

Similar story, went back to the TY one in the end

Is the plug cap cracked as this may arc if the insulation is broken?

Try changing the condenser or ignition coil.

Tragic loss at such a young age.

I think the only Pursang that had a reed valve from standard was the mk 15 which there is very few off in the world. Bully Lover. Didn't realise I had anything special as it came with a box of Bulto bits. The reed valve area is massive in comparison to a trials intake. I had a 325 Model 159 which I sold a while ago to which I fitted the above mentioned Pursang clutch (duplex chain alloy basket) and primary flywheel which looks like the width of the internal part of the flywheel shown above at the side of the engine but mounted externally if you see what I mean, along with a Femsa ignition (I think) as it was smaller than the original. Ignition was the legendary Reg May recommendation of 2.4mm btdc. Never got on with the bike (didn't like the handling) but it was pretty good at hillclimbs.

Dadof2 If you look at the way modern bikes are ridden it is stop, faff around, rev drop clutch and go. Reason is down to tyre and suspension technology. I think the old Bultos in standard trim are pretty wooly compared with other bikes and much prefer the immediate response of a TY twinshock with much of the flywheel weight removed and more importantly it has a smooth light clutch which allows me to ride in a more modern fashion. Not saying your logic is invalid it is just coming from a different direction to mine. I try to make my bike ride like a modern because I think it is more effective for me.

Perfect thanks!

I have a 250 pursang barrel fitted with a reed. It is just so full of transfer ports you would not believe. Cannot see it being suitable for a trials engine but I may just give it a try!!! The standard sherpa barrel has a bolt on manifold and is just crying out for a reed as produced by Keith Horsman etc. If I understand correctly the Aussies are using Sherco reeds?

I hope the reply was tounge in cheek but.... Under any circumstances alcohol and riding do not mix. Samy's reply is a point in case

Does anyone have details on the correct paint code/shade for the "fat" stripe on a 1971 Ossa MAR? Thanks

There were two types of DT and DTMX which is a very different engine From memory the rods are the same in the DT engine but the crank taper is different certainly on the ignition side of a DTMX. .

Many thanks for the replies sounds like a good day out. Question: How original is the Beta? Is it a modified mono? or was the frame originally twinshock, clearly it has had some surgery around the middle. I like the look however.

Pretty alloy one on ebay Sorry looks like it ended Its back on again now

Just to make those of us who could not make the event jealous, what bargains (or not) did you manage to turn up? Be careful the missus does not get to read it!

You also need to check if there are the same number of teeth as the primary drive ratio may be different. There seem to be quite a few on the bay How did you break the inner, its normally the outside that breaks

In my opinion the 205 engine is one of the greats of all time. They are such fun to ride and don't have enough power to get seriously out of shape!

Check that the adjuster screw on the lever is most if not all the way in. This pushes on the master cylinder piston and makes the brakes much more solid as fluid does not seep back into the reservoir, it goes to push out the pads. Two minutes to do and has worked for me in the past when I have bought bikes.

Hundreds of pistons on ebay, especially from US

Interested to know how you built a booth as powder coating is quite expensive. What other equipment is required?

Also cannot believe how good Bou was last night. Leaving the minder on the floor says "I know I am going to get up for certain" Imagine what that does to the mind games of Raga et al when they have just fived it. Mega ride.

http://www.motobecane-trialclub.be/ One of the most complete lists of classic trials in europe. I recommend Aywaille, Bilstain and Abercy as good starting points with plenty of Brits in attendance.

Just bought a 320 barrel for my twinshock. I have read that the early ones did not rev and were modified to improve the situation. How can I tell which is which and what are the modifications required to tune an early one?