Photo by Jan Kopřiva

For chain-driven motorcycles, the chain usually gets most of the credit.

But the chain is just a part of the chain drive mechanism – the sprocket also plays a big part.

Speaking of big, do you know how to determine the size of your motorcycle chain?

In this blog post, you’ll discover:

  • What a sprocket is and where you can find it
  • Where you can easily find the chain link sizing and how to interpret it

What is a Sprocket?

image of motorcycle sprocket

Image by Dennis Larsen from Pixabay

Look at the center of your rear wheel – there, you’ll see a small toothed wheel that the chain (or, more specifically, the chain’s rollers) wraps around.

This wheel is the “sprocket.” In addition to the one you can clearly see on your rear wheel, there’s another one attached to the transmission’s output shaft.

The critical thing to remember about a sprocket is that it goes hand-in-hand with the chain. A sprocket is just useless as a chain is without a sprocket.

It’s for this reason that you should replace sprockets and chains together. A worn-out sprocket will wear out a brand new chain faster, and vice versa.


Where Can I Find the Chain Sizing for My Chain?

image of motorcycle chain

Photo by Jules Amé

If you need to replace your chain, you must know the correct chain sizing.

Fortunately, this is easy – it’s often stamped somewhere on a side plate on the chain itself in the form of a three-digit sequence.

What do these digits mean?

To make it easier to understand, let’s take a chain with a size rating of “535.”

The first digit is the chain’s “pitch” (i.e., the distance between two pins), expressed in one-eighth of an inch.

In our case above, the chain pinch is 5/8 inches.

The remaining two digits refer to the width of the chain’s rollers (i.e., a series of rollers connected by links) expressed in one-eightieth of an inch.

Therefore, a chain size of “535” would have a width of 35/80.