A chain is exposed to dust, rain and heat, and it carries the engine's torque to the wheel. It is also the cheapest major safety item to maintain. The mistake is to treat lubrication as a cosmetic wipe-down and adjustment as a once-a-year job.
Why the chain is a safety item
A chain that breaks can lock the rear wheel, whip the rider or crack the crankcase. A chain that is too tight loads the countershaft bearing and the rear suspension. A chain that is too loose can jump the sprocket or wear the swingarm. These are not hypothetical failures; they are the reason the chain belongs on the pre-ride check.
Wear is gradual, so it is easy to ignore. A chain that has stretched beyond the service limit may still look oiled. Measure it rather than judging by appearance.
Clean without destroying the seals
Most modern chains have O-rings or X-rings that keep grease inside the rollers. A high-pressure washer can force water past the seals; a wire brush can damage them. Use a dedicated chain cleaner or kerosene, a soft brush and a rag. Work on a cold chain and protect the tyre and the brake disc from overspray.
Clean the chain before lubricating, not after. A layer of lube over grit becomes a grinding paste. If the chain is very dirty, clean it in sections, then wipe off the excess before applying fresh lubricant.
Lubricate the right parts
The lubricant belongs on the rollers and the inner plates, not only on the outer side plates. Apply it to the inside run of the chain while turning the wheel, then let it settle before riding. Excess lubricant attracts dirt and flings onto the tyre and the rim.
Chain wax, lube and dry lubricants behave differently. A wax can be clean but may need more frequent application in rain. A heavier lube lasts longer in wet conditions but collects more dirt. Choose for the climate and reapply after a wet ride.
Adjust slack correctly
Use the slack figure in the manual and measure at the specified point, usually midway between the sprockets. Check the slack with the bike on the ground or on a stand as the manual specifies, and with the rider aboard if that is the procedure. A chain that is correct on the stand can be too tight with the suspension compressed.
Loosen the axle, adjust both sides evenly, and check wheel alignment. Tighten the axle to the specified torque and recheck the slack. A chain that is adjusted without alignment causes sprocket wear and can make the bike handle strangely.
Measure wear and replace as a set
Measure the chain over a defined number of links and compare it with the service limit. Check for tight links, cracked rollers, missing seals and rust. A chain that has tight spots cannot be adjusted into health.
Worn sprockets accelerate chain wear, and a new chain on worn sprockets wears quickly. Replace the chain and sprockets as a set when the teeth are hooked, the valleys are worn or the chain is at the limit. Use a rivet link or a clip link correctly rated for the chain.
Checklist
- Check slack and lubrication before every long ride.
- Clean with a soft brush and a seal-safe cleaner, never a pressure washer.
- Lubricate the rollers and inner plates, then wipe off excess.
- Measure slack at the manual's specified point.
- Align the rear wheel and torque the axle.
- Measure chain elongation against the service limit.
- Inspect sprocket teeth for hooks, flats and wear.
- Replace chain and sprockets together when worn.
Questions
How often should I lubricate the chain?
After a wet ride and at regular intervals in dry, dusty conditions. A chain that looks dry or sounds noisy needs attention. Over-lubricating is better than running dry, but excess attracts dirt.
Can I use a pressure washer on the chain?
No. It can force water past the O-rings and into the rollers. Use low pressure and a soft brush, and avoid directing water at the seals.
Do I need to replace the sprockets with the chain?
Usually yes, if they are worn. A new chain on hooked sprockets wears quickly and runs noisily. Inspect both and replace as a set when the wear is significant.
