Bike Sprocket

The bike sprocket is the crucial circular shaped frame piece that drives the chain on a bike. The sprocket comes attached with the right pedal arm. The bike chain will rest on the sprocket and with the movement of the pedal, the bike sprocket will rotate and push the chain forward. The bike sprocket will almost always be located on the right hand side of the bike, and attached to the pedal arm.

This particular bike sprocket is attached by five bolts to the crank arm. We use a 170 millimeter crank arm with 110 BCD. This is a 44 tooth sprocket that's bolted on with five chainring bolts. This is specifically for driving the pedal system on the bike.

Bike Sprocket Sizes

Bike sprocket sizes are infinite. They range from 22 teeth up to 70. And there may be even 80 tooth sprockets out there. The bigger the bike sprocket, the more rotations you're going to get at the rear wheel per rotation at the front. So basically, you increase the diameter of the front sprocket and you increase the ratio to the rear.

A smaller bike sprocket would decrease the ratio. So the smaller you go, the more pedal rotations needed to move the chain a further distance.

Replacing a Bike Sprocket

Over time a bike sprocket can wear out, just like brake pads and tires, a chain is a wear item. So a chain will stretch out. As a chain stretches out, it starts to wear on the gears or the sprocket that it's riding on. So if you ride your chain too long, then you're going to prematurely wear out the sprocket and have to replace it. It's important to note that when replacing your bike sprocket you will likely have to replace the pedal arm as well as they typically come attached. A sprocket should last you three to five years but its lifetime heavily depends on the conditions you ride in.