Kimpex Drive Sprocket 420 - Fits Honda - Rear

How to read the sprocket Charts?

1. Select desired model from the application chart referring to the Make, Model, Year column.
2. Stock size gearing of desired model is listed in column OEM Gearing.
3. All sprockets listed between top and bottom division lines fit selected model. Simply choose preferred ratio from selection guide column and than choose desired R.O.C. sprocket from the appropriate column to the right.

Additional Information:

Gearing selection can affect acceleration, top speed and even handiling.
By changine front and rear sprockets you can alter your bike’s or your ATV's final drive ratio, which in part determines when speed for a given rpm. Gearing ratio refers to the ratio of the rear to front sprockets. For example, a stock Suzuki GSXR600 has a 16 tooth front sprocket, and a 45 tooth rear, for a ratio of 45/16, or 2.81. Substituting a larger front or smaller rear sprocket lowers the ratio (sometimes called “taller” gearing), resulting in more speed for a given engine rpm. Likewise, a smalle front or larger rear sprocket gives less speed for a given rpm (“shorter” gearing).

Performance numbers can be enhanced by sprocket selection to a certain extent, but the overriding factor is your engine’s power and its characteristics. Choosing the correct gearing optimizes your powerband usage, maximizing power delivered to your rear wheel for the given conditions.

Speed for a given set of sprockets is determined as follows:
Speed = (rpm X rear tire circumference X front sprocket) / (primary gear ratio X sixth gear ratio X rear sprocket X 1056)
Stock bikes are generally geared to reach their top speeds at just below their peaks in top gear. Changind to something like 44/17 on GSXR600 woud actually reduce top speed, because in sixth gear the engine wouls spin munch slower and not make enough power to pull its top speed. Shortening the gearing to sy 46/15 would have the GSXR600 passing its power peak early, also resulting in a slower top speed. However, this is where sprocket selection can be advantageous: at a given road speed, and in a given gear, shorter gearing will have the motor spinning faster, where more power is available.

A popular modification is to replace a stock machine’s 530 or 525 chain with a thinner and lignter 520 series chain and matching sprockets.