How do you know what model the motorcycle chain gear is?

.Identification basis method:

There are only two common types of large transmission chains and large sprockets for motorcycles, 420 and 428. 420 is generally used in older models with small displacements, and the body is also smaller, such as the early 70s, 90s and some older models. Curved beam bikes, etc. Most of today’s motorcycles use 428 chains, such as most straddle bikes and newer curved beam bikes.

The 428 chain is obviously thicker and wider than the 420 chain. There are usually 420 or 428 marks on the chain and sprocket. The other XXT (where XX is a number) represents the number of teeth of the sprocket.