The Ultimate Guide to Dirt Bike Sprockets

The most affordable way to alter the power delivery of your dirt bike is by changing the size of your front and rear sprockets, which also play an integral part in getting the power of your engine to the rear wheel. It's why understanding sprocket sizes, as well as maintaining and when to replace them, is incredibly important to know as a dirt bike rider.

 

How do I change my front sprocket?

Changing your front sprocket, sometimes referred to as a countershaft or drive sprocket, involves a super simple process.

The first step is to remove the front sprocket cover if your bike has one so you can easily access the sprocket, as well as removing the chain.

Most modern dirt bikes utilise a circlip to keep the sprocket secure, so you'll need to remove it with snap ring pliers. From there, it's a case of simply removing the old sprocket, cleaning out the shaft, and installing the new one. Remember to reinstall the circlip, followed by the chain and sprocket cover.

 

How do I change my rear sprocket?

Just like your front sprocket, your rear sprocket is also relatively simple to change. It's always best to change both of your sprockets (and your chain!) all at the same time, and it will make the whole process much easier. You'll need to remove your chain and rear wheel, and from there, it's a process of undoing the bolts holding the sprocket in place.

Once you've removed the old sprocket, clean out the inside of the hub and ensure there's no dirt in the bolts and nuts. You'll want to use a medium strength thread locker on each of the bolts before installing the fresh sprocket. It's best to put the sprocket on and semi-tighten all of the bolts to it sits in position.

It's important that when you're tightening the bolts to the correct torque that you do it in a star-shaped pattern - so if you tighten the bottom bolt first, the next one you tighten will be the one above it, then it will be the two that are running horizontally and so on. This ensures the sprocket is evenly tightened and is perfectly straight with the hub and wheel.

The final step is to reinstall the wheel and the chain.

 

What's the difference between a steel sprocket and an aluminium sprocket?

A steel sprocket is generally what most manufacturers will fit standard to their motocross and enduro models, and steel sprockets are a great replacement for the standard OEM one as they're affordable and quite durable.

Aluminium or alloy sprockets, which usually come in a range of colours, are much lighter in weight compared to a steel sprocket and are often the choice by racers who are looking to get the most of their bike. Aluminium sprockets tend to not be as durable as steel sprockets, but the weight benefits generally override the durability for riders and racers.

 

What does gearing mean?

Gearing is a term thrown around a lot when it comes to dirt bikes, and it's the combination of the size of both your front and rear sprockets. The amount of teeth on each sprocket alters the power delivery of your bike to either give you greater top speed or acceleration or meet somewhere in the middle.

If you're new to dirt bike gearing, it's always best to start with the standard gearing combination and make adjustments one tooth at a time from there, depending on what result you're chasing.

A small front sprocket or larger front sprocket will give you greater acceleration or bottom end speed - the general rule is that every tooth you change on the front, is equivalent to changing up to 3-4 teeth on the rear.

A larger front sprocket or smaller rear sprocket will give you more top-end speed, and the same rule applies in that changing the front sprocket offers a larger result than changing the rear.

Choosing what gear ratio is best for you comes down to personal preference, the type of power delivering you want and the type of dirt, tracks and discipline you're riding.

 

How do I clean my sprocket?

It's incredibly important to ensure your sprockets are maintained and cleaned after every ride to extend their life, and it's as easy as hitting both the front and rear with your pressure washer when you're cleaning your bike. You want to remove any build-up of dirt and grime.

Remember to spray your chain with chain lube after washing your bike, which will also prevent your sprockets from corroding.

 

When should I replace my sprockets?

Replacing your sprockets is crucial in ensuring your bikes keeps performing as it should, while also preventing any major mechanicals or accidents while you're riding.

The easiest way to tell if your sprockets need replacing is by inspecting the teeth - if they're looking thin and sharp, and there's rounding inside the teeth, then it's definitely time to replace them.

Since your sprockets and chain all work together, they create a wear pattern within each other as well - this is why it's best to replace your chain, front and rear sprocket all at the same time, even if one of them isn't at a stage where it needs to be replaced yet.

This will allow you to get the most out of all three components, as a new chain on old sprockets can shorten the life of the chain, while an old chain on new sprockets can have the same effect.

 

What are the best brands of sprockets?

The leading brands in sprockets include Renthal, Pro Taper, Supersprox, Talon, Tag Metals, and RK Sprockets, along with JT Sprockets, RHK and Ballards. These are the brands used and trusted by the best riders in the motocross and enduro riding.