To replace a motorcycle chain and sprockets, you remove the old chain, take off the front sprocket cover and the front and rear sprockets, fit the new sprockets, loop on the new chain, join it with the master link, and then set the slack and tighten the axle to the service manual's values. It is a good garage job with the right tools. It is also drivetrain work that can fail dangerously, so know which steps need a torque wrench and when to hand it to a shop.
If you only need to clean, lube or adjust the existing chain, our chain maintenance guide covers that. This post is about the full replacement.
When to replace a motorcycle chain and sprockets
Replace the chain and both sprockets as a set. Chain life depends on how well it is maintained, how you ride and the chain type. We cover timing in how often to replace a motorcycle chain. Signs you should not wait:
- Tight spots that appear as you roll the wheel, or links that kink or do not flex
- Rust, or rollers and plates that look dry or worn
- The chain cannot be adjusted within the slack range on the swingarm marks because it has stretched
- Sprocket teeth that look hooked, sharp or shark-finned
- Missing or damaged O-rings or X-rings
- Chain noise, clunks or skipping under load
The Motorcycle Safety Foundation's T-CLOCS checklist tells riders to check chain tension at the tightest point and to confirm sprocket teeth are not hooked and are securely mounted. Do both before you decide.
Tools and parts
Parts
- Chain kit (chain, front sprocket, rear sprocket) in the correct pitch, width and tooth counts. Our guides to O-ring vs X-ring chains and how to choose motorcycle sprockets help you pick.
- The master link supplied with the chain
- New lock tabs, locking washers, cotter pins or self-locking nuts if your manual calls for new ones
- Thread-locking compound if your manual says to use it on the sprocket bolts
- Chain lube made for your chain type
- Grease for the axle
Tools
- Chain breaker and, for rivet links, a press tool
- Sockets and wrenches for the front sprocket cover, axle nut and adjusters
- Torque wrench (required)
- Large breaker bar for the axle nut and front sprocket nut
- Rear stand or paddock stand
- Chain alignment tool or a straight edge and a ruler
- Wire brush, degreaser and rags
- Safety glasses and gloves
- A helper, which makes the front sprocket step easier
What needs the service manual
| Item | Where to find it |
|---|---|
| Chain size, link count and the right kit | Owner's manual or parts catalog |
| Correct chain slack and how to measure it | Owner's manual and swingarm label |
| Axle nut torque | Service manual |
| Front sprocket nut and rear sprocket bolt torque | Service manual |
| Whether any fasteners are single-use | Service manual |
| How to adjust and check wheel alignment | Service manual |
| Master link type and clip direction | Chain maker's instructions |
Never invent a torque value. A loose axle or sprocket nut is a serious failure. Use the torque wrench and the figures for your model.
Prep: support the bike and take notes
Put the bike on a rear stand so the rear wheel is off the ground and stable (our FAQ on whether you need a motorcycle lift compares stands and lifts). Photograph the chain routing, the sprocket cover and the position of the adjusters. Count the links of the old chain, and note how many marks the axle sits at on both sides of the swingarm. These details help you set the new chain up correctly.
If the bike has a belt or shaft drive instead of a chain, this guide does not apply.
How to replace a motorcycle chain and sprockets: step by step
1. Remove the front sprocket cover
Take off the cover that covers the front sprocket. On some bikes you also need to move the shift lever or a clutch slave cylinder. Take pictures first. If a hydraulic line is attached, do not disconnect it. Unbolt and move the part aside.
2. Loosen the front sprocket nut while the chain is on
With the chain still on, put the bike in gear (and the rear brake on, if your manual allows) and loosen the front sprocket nut and the lock washer. The chain gives you something to hold against. If the nut is very tight, a helper holds the rear brake or a rear wheel lock.
3. Loosen the axle and chain adjusters
Loosen the rear axle nut and the adjuster locknuts, then push the wheel forward to give the chain slack.
4. Remove the old chain
Lift the chain off the rear sprocket. If it has a clip-type master link, remove the clip and pull the plates. If it has a riveted link, you will need to grind or cut one rivet or break a link with the chain breaker. Wear eye protection.
5. Remove the sprockets
Slide the front sprocket off its shaft. For the rear sprocket, take off the wheel, lay it on a clean surface and remove the bolts or nuts. Some rear sprockets mount on a carrier with a cush drive, which you should also inspect. A worn cush drive rubber or damaged carrier is a reason to see a shop.
6. Clean and inspect
Clean the sprocket seats, front shaft splines and the sprocket cover area. Check the front shaft splines for wear and the countershaft seal for oil leaks, since leaking oil can ruin a new chain. Inspect the axle, adjusters and swingarm for damage.
7. Install the new rear sprocket (torque wrench step)
Mount the sprocket the correct way round, with any stamped marks facing out as the maker says. Fit new lock tabs or nuts if required, apply thread locker if the manual says to, and torque the bolts to spec, tightening in a star pattern.
8. Install the new front sprocket (torque wrench step)
Slide the sprocket on, fit the lock washer or tab, and start the nut. Final torquing is easier with the chain on, so you can do it after the chain is fitted. Torque to the value in the manual and bend the lock tab if there is one.
9. Measure and size the new chain
Wrap the new chain around the sprockets and check the link count against the old chain or the manual. If the new chain must be shortened, use the chain breaker and keep the correct number of links for a master link. Do not cut more than needed.
10. Fit the master link
Pass the chain through, join the ends with the master link and install the plate and clip. For a clip-type link, the closed end of the clip points in the direction of chain travel, which the instructions show. For a rivet link, use the proper tool and measure the riveting as the maker describes. If you are not confident here, have a shop do the final link, because a chain that comes apart at speed is dangerous.
11. Set the slack and alignment
Put the wheel in the approximate position, then set the slack with the adjusters to the measurement in your manual, checking at the tightest point of the chain as T-CLOCS describes. Use the swingarm marks or an alignment tool to keep the wheel straight. Recheck the slack after tightening the axle.
12. Torque the axle and final nuts (torque wrench step)
Tighten the axle nut to the spec in the manual, then the adjuster locknuts. Fit a new cotter pin if one is used. Recheck the front sprocket nut and the sprocket cover bolts.
13. Lube and test
Lube the chain according to the chain maker. Roll the wheel several turns and recheck the slack at different points. Start the bike, run it in the air on the stand in first gear and watch the chain run smoothly before you ride. Keep hands, rags and loose clothing well away from the chain and sprockets while the wheel turns.
Break-in checks for a new chain
A new chain stretches a little as it beds in. Check the slack after the first short ride and again after the first few rides, then keep to a regular schedule. Our chain maintenance guide explains cleaning and lubrication intervals.
Common mistakes
- Replacing only the chain and leaving worn sprockets
- Skipping the torque wrench on the axle and sprocket fasteners
- Reusing a master link or the old clip
- Fitting the clip in the wrong direction
- Setting slack at the loosest point rather than the tightest
- Misaligning the wheel
- Overtightening the chain, which strains the bearings
- Forgetting to check the countershaft seal for leaks
Cost: DIY or shop?
A chain and sprocket kit costs more than most routine parts, and the price varies a lot by brand and chain type. A shop adds labor, and some rivet-link work or cush drive repairs add more. See our chain and sprocket replacement cost guide for typical ranges. Varies by bike, region and shop.
When to see a mechanic
Leave the job to a shop, or stop and call one, if:
- You do not have a chain breaker, press tool or torque wrench
- You cannot get the axle or front sprocket nut to the manual's torque
- The cush drive, rear sprocket carrier or countershaft splines are worn or damaged
- The countershaft seal is leaking oil
- The wheel will not align or the slack will not set within the manual's range
- You are unsure about the master link
- The chain makes noise, jumps or binds after the job
Do not ride with a questionable drivetrain. Our maintenance services page lists shops that do chain and sprocket work, and you can compare shops in the motorcycle repair directory.
Quick checklist
- Replace the chain and both sprockets as a set.
- Get slack, torque values and alignment from the manual.
- Use the new master link and fit the clip correctly.
- Torque the axle, sprocket nuts and bolts with a torque wrench.
- Lube the chain, then recheck slack after the first rides.
Frequently asked questions
Should I replace the chain and both sprockets together?
Yes, as a set. A new chain on worn sprockets wears out faster, and worn sprockets chew a new chain. Replacing all three at once is the usual advice.
Can I use the old master link on the new chain?
No. Use the new master link that comes with the chain, and fit it the way the chain maker and your manual describe. Fit the clip in the correct direction.
How do I know what chain length to buy?
Buy the chain by the pitch, size and link count listed for your bike, which your manual or the parts catalog gives. If you change the sprocket sizes, the link count and slack can change, so check before you cut.
Do I need a chain breaker and riveting tool?
For a clip-type master link, a chain breaker is enough to shorten the chain. A rivet-type master link needs a press tool and takes skill, so many riders have a shop do that part.
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