Extreme Downhill Kawasaki KX125 mountain bike with Rohloff Speedhub gearbox

[RichPober]

Artist: Drowning Pool

Song: Think

Album: Desensitized

[RichPober]

As you're only going up 25cc, the gearing should stay about the same.

Gearing is easy to work out. Just calculate the ratios between the drive sprocket and the driven sprocket and compare them to the standard set-up. If I need to alter the ratio then I increase or decrease the number of teeth on whichever sprocket it's easiest to replace with either an off-the-shelf gearbox sprocket or a custom made/off-the-shelf rear wheel sprocket.