sprocket sizes??

James

Staff member
What bike? What are the stock sprocket sizes? What type of riding?

Basically if you want higher top speed/less torque you go smaller on the rear, less speed/more torque you go bigger on the rear.
 

SRAD97750

Moderator
Staff member
Changes in sprocket size can do many wonderful things and fine tune how the bike puts the power to the ground.
Changing the rear sprocket more directly affects top speed in each gear.
Changing the front sprocket is more dramatic and actually changes the characteristics of how the bike makes power, due to inertia.

You can get nearly the same final drive ratio by changing the front OR rear sprocket, but how you want it to "change" determines which sprocket to alter.

Example.
15X50 is 3.33
and
16X53 is 3.31
They are very similar ratios, but have dramatically different effects on the bike.

The 15 tooth front sprocket will be easier to turn because it has fewer teeth (distance) per revolution.
The 16 tooth must pull the extra distance in the same revolution. (Mathematically requiring more power to do the "work.")

Even though these "distances" are nearly equaled by the rear sprocket size, the inertial effects are greater at the engine sprocket.

I would expect a 15x50 to "rev" faster than the 16x53 setup.
Alternatively, this 16X53 can be used to smooth the hit of the engine, just like a flywheel weight. But the weight is at the counter shaft.

Trial and error for every bike is different.
-BIG DAN:thumb:
 
Last edited:
Dan nailed it! I'm currently running 13/49 on my bike, for most of last year I ran 14/53. The ratio's were quite similar, but I didn't like the 14/53 because it felt like it took the oomph out of the motor down low but I still needed the top speed (I ride desert) so I left the front stock and changed the rear to a smaller sprocket.
 
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