sprokets..smaller/larger

[<DarreN123>]

im very new to dirtbiking and i have a 12 th on the front and a 50 th sproket on the rear...and i dont do track..i just bought the bike (99rm125)...so if i went smaller rear/larger front sproket would that help me at top speed or for woods/trail at all?...because i top out pretty quick?...or do i just leave it alone?

 

[Jaybird]

I would suggest you change out the front sprocket to a 13t. What you have now is a 4.17:1 ratio, which is fairly low. If you went to a 13t with the 50t rear, you would net a 3.85:1 ratio. This would allow you more top end speed. It also would mean less torque down low, but 3.85:1 is a good ratio for your bike and you would probably enjoy the change.
Also, a 12 tooth front sprocket is harder on your chain than a 13 tooth is. Your chain, and as a result your sprockets, will last longer with a larger front.