Motorcycle chain and sprocket kits

A motorcycle chain and sprocket kit, sometimes called a final drive kit, pairs a chain with its two sprockets, already matched for one model and set of years. The kits here are from RK, for road bikes, adventure bikes, customs and the odd quad. Getting it right is mostly about everything matching your bike, so here are the questions riders ask most.

What has to match your bike

• Pitch: the distance between rollers, named with three digits: 420 or 428 on small bikes, 520, 525 or 530 on mid-size and larger ones. All three parts share the same pitch; with a different one, they will not mesh.
• Teeth: the small front sprocket sits on the gearbox output and the large rear sprocket on the wheel. Their tooth counts set the final gearing, so if you do not want to change it, the kit should keep the same numbers as your bike.
• Length: the chain is measured in links and comes sized for that gearing.
• Version: RK offers Standard, Reinforced and Racing 520 kits; the differences are set out under RK chain kits.

Common questions

Can I replace just the chain?

You can, but it rarely pays off. A stretched chain wears the teeth to its own shape, and a new one fitted over them does not sit properly: it gets noisy and stretches quickly. Renewing all three parts at once means they all start their working life together.

How do I know the kit is finished?

With the chain correctly adjusted, pull it backwards at the rear of the sprocket: if it lifts away enough to show much of a tooth, it has stretched. Other signs are adjusters at the end of their travel, links that stay seized and sprocket teeth that are pointed or hooked.

What if I want different gearing?

One tooth less on the front sprocket, or two or three more on the rear, makes the bike accelerate harder and rev higher on the motorway; the opposite makes it taller-geared. Bear two things in mind: several extra teeth on the rear may call for extra chain links, and on bikes that read speed at the gearbox output, the speedometer will no longer be accurate.

Clip or rivet link?

A clip-type master link goes on with pliers and is typical of small chains and off-road use; the clip is fitted with its open end facing away from the direction of travel. A rivet link is the norm on powerful bikes and needs a dedicated tool to close it properly. If you do not have one or have never done it, fitting is a job for a workshop.

Once the kit is on, set the slack with the chain adjusters; and if your bike does not run a chain, motorcycle drivetrain explains the alternatives.