15-36
wht is the best sprocket combination for Yamaha 135 answer: depends on your tire size you use at the back.try the different sprocket gear ratio listed on the yamahat135.com or see the link below
The best sprocket comb for lc135 is 15 37 which the ratio is 2.47
Best sprocket combi for rj 110cc - 14 36
it depends on your rear tire size and weight.............................