I am trying to buy a few sets of rollers from scooter center and 1 the 13g are 20x17 and the 12.5 are 19x17.What would happen if i was to mix the two sets seeing that the have two different diamentions ? cratch:
If one is bigger than the standard size they won't fit on the variator. If one is smaller than the standard size they'll rattle like f#@k and won't help in any way. Buy the correct size for your bike.
the 20mm ones are 180 ones i belive. keep to stock size unless your transmition is setup as a 180. 13g should be ok.