Where To Buy Larger Rear Sprockets?

[plugman]

I have a Montesa 315R that I was told is an 00/01 (2-Stroke model) & today I dropped the 10T front sprocket down to 9T & am liking the results although not quite a big enough drop I don't think & am looking at purchasing a much larger rear sprocket.

At the moment I am running the stock 40T rear sprocket but would like to go up to something as high as 45T although not too too sure if the chain will be long enough to support this. At the moment I have the rear wheel as far back as possible to support the 9T sprocket so am thinking will definately need to go up on the rear but the most I can see anywhere is 42T.

I have no ambitions of competition level trialing & just ride the bike for fun so think that going up to a 45T will make the bike very very lively in 1st & a lot more controllable in 1st gear wheelies also with the 9T on the front also.

Any recommendations / links to shops that sell larger rear sprockets?

I have found the following that are said to fit an 05-11 4RT but also unsure as to how sprocket sizings work between models!

44T - http://www.ebay.co.uk/itm/160933966419

46T - http://www.ebay.co.uk/itm/170861683618

48T - http://www.ebay.co.uk/itm/150742663352

[2stroke4stroke]

I imagine any of the Googleable sprocket suppliers could do one in the size you want but the gearing will then be far too low to do wheelies in 1st. If "wheelies", as opposed to just raising the front wheel, is what you want to do, then 3rd is about the lowest practicable gear anyway.

[andy m]

http://www.talon-eng.co.uk/product_category/sprockets/trials/

[bilks]

http://www.bvm-parts...product_id=2270 but going down 1 tooth less on the gearbox,is roughly equal to 3 on rear. the other sprockets listed are no good to your machine,as they are 4 bolt fixing,as yours is 6. Edited June 3, 2013 by bilks

[plugman]

Thanks for the links guys, will check them out come morning. When I say that I like to have fun on the bike & don't intend on going competition style I mean anything from small jumps / logs / hill climbs etc. I've had a few trials training sessions (Group & one-on-ones) just to get the grips of trials & simply enjoy riding the bike & overall I'd like to try out anything. At the moment I quite like the idea of circle wheelies & stunting on the trials bike which is probably how this idea of such extreme gearing came along but at the same time would like the bike rideable. Unlike a sport bike I have absolutely no requirement for speed on this bike, I have enough fun below 20mph so losing top end wouldn't bother me at all as it wouldn't if I had to be in 3rd to jump a log!

[plugman]

http://www.bvm-parts...product_id=2270 but going down 1 tooth less on the gearbox,is roughly equal to 3 on rear. the other sprockets listed are no good to your machine,as they are 4 bolt fixing,as yours is 6.

Thanks for this link, do you happen to know if the 48T sprocket would be ok with the current / stock chain size of the Montesa (-1 +8). Sounds like I may be needing a longer chain?

[p@ul250]

Yes you will need a longer chain. But it's always a good idea to fit a new chain when fitting new sprockets anyway.

[plugman]

Yes you will need a longer chain. But it's always a good idea to fit a new chain when fitting new sprockets anyway.

Thanks, would you happen to know of a way to calculate what size chain I would require on a -1 +8 fitting?

[plugman]

(If the +8 is too much I will likely go back to a 10T front & test between)