found this on facebook:
lil info about sprocket(garari) sizing
Motorcycle Sprocket sizing explained:
The gears with teeths you see working with chain are called sprockets.
We have two sprockets one at front and one at back.
Altering size of front sprocket:
Bigger front sprocket will move your power in higher rpms (also increases top speed)
Small front sprocket will move your power in lower rpms (also reduces top speed)
Altering size of rear sprocket:
Bigger rear sprocket will result in better acceleration, (increases overall torque, reduces top speed)
Smaller rear sprocket will result in higher top speed, (decreases acceleration and torque which is the strength of power).
We change and match the sprockets according to our requirements also matching the top speed with engine power (whether if our engine will pull such a gearing). If you put a wrong combination it will result in power loss, difficult drivability in low rpms, too long gearing that an engine cant pull or too less top speed.
There are Sprocket calculators out there (online) which helps you fine tune your gearing and selecting the optimum size of sprockets. Always use them before changing your sprockets and consult an expert