The bigger your front sprocket is the faster the top end, the smaller it is the faster the acceleration .
The bigger on the back the quicker the acceleration the smaller the better the top end.
The standard set up is 16/39
39 tooth sprocket on the back , 16 on the front.
Change the size of sprockets for more or less accelleration/top end.
|aprilia rs125 sprocket mph graph|
see the sprocket calculator
the aprilia rs125 blog
a sprocket mph calculator
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BUY the ultimate Aprilia RS 125 workshop manual bundle HERE