Gearing for 18 inch Tires

[mxturd]

We ride alot of ATV rodeos, here in Missouri, and I just put some 18 inch tires on my bike. My question is about gearing for the tires, mods are in my signature.  Our rodeos are a 5 event reace, 4 of the evens are basically different barrel configurations that you negotiate and for time, the last event is bracket drag race.  I have stock gearing now, but with the tire change should I go up a tooth on the front or ?  Anyone that may have experience with 18 inch tires please help.  Thanks

[Young Guns Racing]

This is going to be more of a test and tune thing for you now. Snaller rear tire will make on revolution fasyerthsn ur 20in tire so u are gaining a small ammount of bottom end. It depends on what you want out of ur setup. I have a 2012 yfz450r as well, tons of mods and shes makin 52hp at the wheels. Way betyer than stock, I also dropped a tire size and to help wil spinning so much out of the gate I slapped on a +1 front sprocket

[mxturd]

So with switching to 18s from 20 I already in a sense loweredd the gearing.  I noticed it winds up really quick and alot of wheel spin  I suppose Ill try a tooth higher in the front.

[sheerider11]

So with switching to 18s from 20 I already in a sense loweredd the gearing. I noticed it winds up really quick and alot of wheel spin I suppose Ill try a tooth higher in the front.

This isn't my strong point, but there is a gearing calculator. Would suck if you switched the tires and changed gearing to be back at the same point. So figure out what you want to do and work with that

[possum]

19-39