A forum for owners of Yamaha TTR250 trail and enduro bikes!

nelly · Senior Member

gearing again , sorry chaps

TTRfan · Super Guru

See here - sounds like 112 or 110 link chain is needed.

Hopefully someone with practical experience will come along to confirm!

Brian

nelly · Senior Member

thanks brian
yes I saw that and thought id found my answer until I saw "correct by Yamaha but some need 112"
so a 112 then and cut if needed,
thanks

peteBLUEttr · Super Guru

100mm is quite a tall profile tyre so it would have to go back in the swinger more than the average put it that way.

The thing with fitting a 52 sprocket is the chain will bear more heavily on the rear chain guide and some people feel when fitted, that it is enough to warrant lowering the guide see here : ttr250.activeboard.com/t57684118/lowering-chain-guide/

13/48 would work out only a touch higher gearing than 14/52, as the general rule is 1 tooth down on the front equals similar to 2-3 up on the rear.

You are going to need to play about with length a bit I think, Chain aint too much of an annoyance to break, if you cant be bothered to grind the chain rivets flat then get hold of a chain breaker with a hardened extractor.

peteBLUEttr · Super Guru

Dunno what anyone else thinks, but I personally think it is better to run a 13 tooth front sprocket because a 14 runs pretty close to the case saver, and if anything ends up running through there on the chain, there could be possibility for foul up...

nelly · Senior Member

cheers peter
hmmmmmm , maybe 13/48 is the way to go then, il more than likely just fit a 13t up front to start with and see if its any more lively off road, but I cant see it making much difference tho,
hopefully they.ll be enough adjustment on the snails

I will report back as and when

thanks all

petenz · Super Guru

I buy 120 link chains then shorten them to fit...

..

Cookie123 · Newbie

Nelly,

How did you go with just fitting the 13t up front to start?

Was thinking of doing the same thing this week, but its its no good ill by a 48 or 50 for the rear.

I only use my bike of road so want something for those tight steep tracks

peteBLUEttr · Super Guru

Anything over 49 ish tooth you may have to modify your chain guide. Just make a search on here to verify.

nelly · Senior Member

Cookie123 wrote:
Nelly,

How did you go with just fitting the 13t up front to start?

Was thinking of doing the same thing this week, but its its no good ill by a 48 or 50 for the rear.

I only use my bike of road so want something for those tight steep tracks

it does make a difference on acceleration and will still go 70+ on the road,although ive noticed that I have to run the chain very slightly tighter than before ,because it rubs on something on deceleration,probably the top of swing arm,when I'm ready for a new chain il look into going a couple of teeth bigger on the rear, maybe ?

our lads raid with 15/48 seems lower geared than mine but ive not had chance to ride it any distance on road ,but il be interested to know what it cruises like

hope that helps