Another sprocket question

[katoranger]

Originally Posted by alex_in_az

I run a 15 front and 36 rear. my bike will pull to 8200 rpm in top at about 78mph, it's a 200 CG engine with a 30mm mikuni and a couple of other simple mods

You have a bit of weight advantage with yours. 15/36 equals 2.4/1 ratio. 17/46 equals about 2.7/1 and 17/42 equals about 2.45/1 ratio. The 2.7 seems to work well for the dual sports offroad.