Hello all I am new to dual sporting, and had a question about changing sprockets, what would happen if I went down one tooth on the front or went down a few teeth in the rear alone. It's a 2010 250s all stock except air box mod.

 

You need to do the math. I made an excel spread sheet to do those calculations and it would work for your 10, since I have it for an 09.

If you go smaller front it will gear lower, more off road.

Smaller on the rear will gear higher, more highway.

I did some numbers and have recently picked up a 39T rear along with a 13 front and a 16 front. The 16/39 is as high as you can gear without a custom sprocket. The 13/39 is just a shade lower than the OEM 14/52. I figured it would be fun to play and still need to get off road to see if that gearing works well enough for what I will be doing. If not, I may have to go up on the back.

What you do depends on what you want. If you want my excel spreadsheet PM me. It allows changes for everything. In other words you can do tire sizes if you know the OD as well as the gearing. I originally wrote it to do tire calculations for my 650 when using radial street tires versus the dual sport tires.

 

You could also try this Gearing Commander: Motorcycle Speed, RPM, Chain & Sprockets Calculator