Twinshock

Just thought I'd drop a quick line here to thank the guys at In-Motion. Was having issues trying to source the correct cable for my Cota 247C. Was on the phone for 20 mins today whilst the poor guy at In-Motion went thru the possible cable Montesa permutations (lots!) and even went and got a bagged up cable up to measure the free cable for me, on the one we thought should fit, may not of been correct, he wasn't to know before opening it. Great service and thanks PS...now if you guys could open a well priced Trade Motor Factors near Diss with '30 minute vans' I'd be in heaven...

Thought I'd post this here rather than Monty section as most t/s's run drums. Bloody odd this. Front brake creaks when applied when stationary and the lever feels spongy. The drum lining isn't split which was my first thought. Stripped the brake down and still does it...bit of a strange one? When moving the brake works ok but is still spongy. Any ideas welcome no matter how bizzare

I've dragged the old units out the spares box and wonder if anyone can recall what pressure they should be pumped to. I did read somewhere that 200 psi was the figure but that seems more like that for air spring units and i certainly don't think my local Fox dealer had the equipment to pump or measure to that sort of pressure when he set them. I may have had a manual but that will be long gone. Any advice appreciated.

would of said "you lucky people"..... found this whilst browsing, thought I'd bookmarked it, then lost it and took me hours to find it again. A 'Which Bike' test of the 1978 Monty 247 which I now know was called the 247C, the 'C' standing for competition. So it must be suitable for trials I guess cota 1.pdf

Been offered a Cota 247 1978......up on its toes, easy starter, good compression and running ok, sound clutch, no dragging....tidy but unrestored. I could trial this bike next weekend....if ya fussy yes you would strip n tart her up. I've had a short ride on flat grass and feels small and well balanced. What is the form on these old war horses? I know nothing about them....are spares still an issue....is there the equivalent of the most fantastic 'Mr SWM' Mr Matthews behind early Cota's offering support 'n spares? Cheers guys PS my normal ride is an SWM...the Cota felt dated but quaint against the Speedy which won't be going anywhere...the Monty would …

Sorry double post

Not many of these to see these days but I have one that is misbehaving. Practicing a few weeks ago I lost the ability to shift gears. Didn't get banged. Lever resisting up a down movement on the spring but no selection. Thought the problem would be the locknut on the eccentric cam coming loose. But not the problem. Have stripped the mechanism in the primary case. Nothing seized and no broken springs. Moving through the range of adjustment allows a setting that will allow going up the box or down but not both. All gears select easily using the square 8mm peg. Timing marks lining up correctly. No noises from gearbox so I think it's the mechanism in the primary case. Any tri…

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…

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.

Well I've got to say im surprised, i posted a request for info on the Elstar trial bike a while ago, over 700 views but not a thing, usually the combined knowledge of the forum can come up with something. Thers a good article about the bike on the BSA Otter site if anyones interested, and if you have one of these bikes or know anything about them I'd be very intrested in hearing from you

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

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 …

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

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 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.

Hey all, I have just acquired a early 80's Merlin and need some engine parts. Namely a piston kit and possible con rod kit. - anyone know of a supplier? - should these bikes have a chrome bore? It is a very early bike. #7 off the production line I believe.

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…

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