Twinshock

Hi All Hope I can pick some brains on here. I've just finished rebuilding an '83 MH349 and am now in the process of "shaking it down" in preparation for my glittering career in twinshock trials (maybe). I come from a motocross / enduro background and have no experience of trials bikes, but one thing I've noticed is the bike is really noisy. I don't have access to a DB meter, but I'd reckon it's as noisy as a loud 2 stroke motocrosser. It's got a brand new WES tail pipe from InMotion on it, mated to the original front pipe. It's not leaking anywhere and the WES silencer has got packing in it. Bizarrely, the noise seems to be coming from the front "expa…

Just wanted an opinion from someone who has experience on both of these bikes.I have a TY and would like to find a MAR and just wondered how they compare.While on the subject,was the 350 MAR better than the 250?

Hi I've got a Merlin DG 350 twinshock which has a worn out carburettor,do I go with a new one the same as the original or try something else? If so what has anyone tried and tested.Any feedback would be helpful. Also what's the engine spares situation like if I need anything at a later date. Cheers.

The carb on my Montesa Cota is worn out and distorted. The bike is a 1972 Montesa Cota 247 frame number 21M8xxx (mk4 silver frame). It currently has an Amal Mk1 627/414 which doesn't seem to be listed on the Amal website, is this really a Cappra or scorpion carb? I'd like to replace the Amal, can anyone advise what the correct carb is for that year i.e. 627/427 etc? The Amal site offers a number of options for a '72. I'd like to keep it simple and original and stay with the Amal. Thanks

Hi guys, I've just fitted a Gremica 125mm front hub to a Bantam to try to improve the braking power over the previously fitted Montesa 110mm hub. The hub had very little wear, max dia was measured at 125.5mm and surface was free of any damage, I used a new NOS brake plate and cam assembly with oversized shoes arched to to fit the hub. The lining material was recommended by Villiers Services to be the best for trials. I also opened the brake plate spindle hole 0.020" to allow the plate to centralise with the brake on before tightening the spindle. Now what I expected was a significant improvement in braking power but in fact the braking is no better! New wheel beari…

So a rather rusty but very cheap CG miraculously appeared in my garage. I'd had one as my first road bike when I was seventeen and went everywhere on it. But I was a bit unsure of what to do with this one. It was too rusty and worn to keep as it was so it needed sorting out. A couple of mates have RTXs which they are putting on the road and that was when the penny dropped. The CG needed to become the trials CG! Or rather trials-ish CG. I've a '03 Sherco for the proper stuff but I've always wanted a bike on the road that had decent trials ability. So I started to strip the CG and compile a list... and that's about as far as I've got ? So I think I need a 21" wheel, a …

Recently finished building this bad boy

In short. Are there any lists charts or web sites pages etc, that list what shocks were fitted as standard to trials bikes of various brands, and any similar info on how to ID the various makes of shocks and iding them besides the obvious looking for a name or number on them.

Can you refurb 1973 shocks? There is no damping left on mine!!!! If not what to replace with Thanks

I have led a sheltered life, in my sporadic trials carrer spaning close to 5 decades now i have only experience with a few engines. BSAs bantam cota 123 and ty250B s oh and a ty80 Now recently considering an engine swap then deciding against it, i got to thinking did the members of this forum have any particular engine type or capacity that they would chose for their ulltimate air cooled twin shock project. What engine what capacity and why exactly detailing what it is about its power delivery torque respone etc etc you like so much about this particular engine.

Potentially stupid question, but... What is Octane booster and should I be using it in any of my bikes? (fantic 200, Yamaha ty250 mono and 1954 tiger cub) Thanks Sam

I'm in the process of rebuild the engine on my 250 Armstrong so I have the rolling chassis sat empty and want to take the opportunity to move the footpegs a little. The frame was advertised as being Reynolds 531 and I always thought you could only braze 531. However it doesn't look like any of the frame is brazed by Armstrong. Does anyone know if all the frame is 531? In particular what material is the flat steel plates the footpeg brackets are mounted? I will also think about altering the steering head angle at a later date so any info / advice re welding or brazing in that are will be welcomed, thanks.

We were given an old RTX 212 trials, Its in decent overall condition been sat in a shed for years. I got it as a summer project to keep the kids occupied and give them another bit different bike to play with compared to the sherco 125 they share now. Got it running with a carb clean and a bit of tinkering, engine is fine clutch ok and it goes through all four gears. Very little info on these things on the net, some talk on here and a few pdf files and brief history on them but other than that its Russian forums and google translate for further info. The bikes frame is chrome and cleaned up nice the plastic and fibre glass pannel work did not fair so good and…

Hi All I am attempting to rebuild a 348 gearbox, 1 How much endfloat on gear shafts ? 2 which side do I fit shims ,or do the shafts sit centrally shims both end? Any advice gratefully received Cheers

I purchased this today as I fancied a twinshock mont and a bit of a project The frame and engine number is 21m51607 I've looked online and all I can tell is its a 247 no idea about how you date it If anyone could shed any light on it I'd appreciate it because I'll be needing a few bits and bobs Thanks in advance

I am rebuilding a Montesa 242 and although the bike is low hours and relatively untouched, when I washed the clutch case and gearbox out with petrol, what looks like thrust washer dropped out of the primary case, evidence as you can see, a ham head took the clutch apart, the nut was also loose, has anyone any advice on dismantling these clutches please? Many thanks 242.pdf

Hello everyone and all. This is my first post and I'm sorry it's turned out to be a question. But I could do with a little help identifying what cc my ossa is. Now I have had a look throughout the forum for a few months now as well as the rest of the web but to no avail, so please forgive me if the info I require is on here somewhere already I've just failed to find it. It was sold as a 250 but after a quick web search I thought it to be a 310. But now after more searching and reading I'm left a little confused. This is what I know: it's a mk3 frame, with the layed down shocks. Both frame and engine have matching numbers starting with 57****, which the charts I've c…

This might sound like a stupid question i am seeing more and more twinshock bikes with what looks like a honda or pit bike engine these bikes use the frame as a fuel tank are they hime made specials or can you buy they ,they look light a fun to ride.

Is there anyone out there who has an Elstar Trials or knows someone who has, pictures, sales info etc, info on these are hard to find, Don Morleys book and the "Otter" web site are the only source's i have found, any help would be greatfully received

Hi folks, does anyone know what thread is used on the top of the yoke stem, the one that holds the top yoke to the steering stem? Further to that, does anyone have such a nut, and better yet lend or sell me a die to cut this thread? Thanks in advance for any help. Dave