I'm working on some gearing changes. Does anyone remember how the math goes? One tooth on the front is worth three on the rear?

R D
All about ratio. rear # teeth divided by front.EX 51/14=3.6428 add tooth to rear gets 3.7142. Spent a lot of time with a cr that was between teeth on rear so changed both rear and front to get ratio to eel correct to us,strange MX rags thought gearing was "right on" ??? JR

Perfect, thanks!

Info on changing tire sizes very useful. Last year Ray had a flat tire and used a spare 450 wheel set on the arena cross track, the 250 seemed to respond well but tried the same thing outdoors with poor results.