Drive chain: the maintenance everyone postpones

It is the hardest-working part on your motorcycle, the only one transmitting every newton-metre to the ground, and the only one no warning light watches.

A chain gives no notice. It stretches slowly, it develops tight spots, and then one day it skips a tooth on corner exit — or it snaps and takes the casing with it.

What kills a chain on track

On the road, a chain dies of corrosion and neglect. On track, it dies of load.

Every acceleration stretches the links along their axis. Every downshift loads them the other way. Add heat — lubricant literally burns off above 150 km/h — and rubber dust that sticks to the grease and turns the chain into abrasive paste.

A quality chain lasts roughly twelve track hours. That is six to eight track days: a good season for a regular rider.

The three checks

Tension, before every session

Not once in the morning: before every session. A chain heats up, slackens, and the swingarm works. Measure the free play at the tightest point of travel — find it by turning the wheel, it always varies from one half-turn to the next.

Too tight and it eats the output shaft bearing. Too loose and it whips and skips. Both extremes cost more than the chain itself.

Lubrication, hot and afterwards

The right moment is straight after riding, while the chain is still warm: the lubricant penetrates between the seals instead of sitting on the surface. Greasing a cold chain before setting off mostly decorates the swingarm.

Sparingly. Excess improves nothing and flings onto the rear tyre.

Stretch, once a season

This is the check that actually decides. Measure twenty links and compare against the new specification: beyond 2 %, the chain is finished regardless of how it looks.

A quick field check also works — pull the chain away from the rear of the sprocket. If you expose more than a third of a tooth, the whole set needs replacing.

Why all three parts go together

It is the question asked at every workshop visit, and the answer never changes.

A worn chain has cut its own footprint into the sprockets. Fitting a new chain onto worn sprockets imposes a pitch that no longer matches: it wears out in a few hundred kilometres instead of twenty thousand.

The apparent saving of a hundred pounds is therefore paid back at the next kit, two seasons early. Chain, front and rear sprockets are replaced together — any workshop will tell you, and they are right.

Steel or aluminium

An aluminium rear sprocket saves around 700 grams at the wheel's periphery, which you feel turning in. It also wears twice as fast.

For track-only use, where you replace often anyway, that is defensible. For a motorcycle that also sees the road, steel remains the sensible choice.

Track it rather than guess

Twelve track hours is not something you total in your head after three seasons. That is exactly what a logbook holds for you: fitting date, kit reference, and hours accumulated since.

StemmaPass gives the chain its own category and its own service scale — and warns you before the outing, not after.