OEM info is the chain and sprocket sizes that come on the motorcycle from the factory. Pitch is the chain size, Front is the number of teeth on the front sprocket, and Rear is the number of teeth on the rear sprocket.

Conversion is changing the chain and sprocket pitch to a different size.
Please note, when switching to a different pitch size, all three components (front sprocket, rear sprocket & chain) must be the same pitch.

The benefit of switching to a smaller pitch is weight savings. However - switching to a smaller pitch will result in decreased chain and sprocket life from the OEM size.
CAUTION! Do not switch to a smaller chain size that is not rated for the cc/horsepower of the motorcycle being converted.