Every chain drive motorcycle sold in the region comes with a service interval written by someone who was thinking about sealed roads. On murram, that interval is wrong by a wide margin, and following it is the single most common reason a chain and sprocket set that should last twenty thousand kilometres is finished at seven.

Why dust is the actual problem

Chain lubricant is sticky by design, because it has to stay on a part that is spinning. On a dusty road that stickiness collects fine grit continuously. Within a couple of hundred kilometres the lubricant is no longer a lubricant. It is a paste with an abrasive suspended in it, held exactly where the rollers meet the pins, which is the one place you do not want an abrasive.

Adding more lubricant on top does not fix this. It thickens the paste. The chain looks well cared for and wears faster than a dry one.

The interval that works

On mixed tarmac and murram

  • Clean at 300 to 500 km, sooner if you have ridden a full day on dust.
  • Clean means remove the old lubricant, not add to it. Paraffin and a stiff brush is enough.
  • Lubricate only after the chain is clean and dry, and only on a warm chain.
  • Use less than feels right. Excess is what collects grit.
  • Wipe the excess off the side plates before you ride.

Measuring wear honestly

Pull the chain away from the rearmost point of the rear sprocket. If you can see daylight past the tooth, the set is finished. For a number rather than a judgement, measure a span of twenty links under light tension and compare it against the same span on a new chain of the same pitch. Two percent longer is the replacement point, and past that you are wearing out sprockets that were otherwise fine.

Replace the chain and both sprockets together. A new chain on worn sprockets destroys itself in a fraction of its life.

What this costs you

The honest trade is about twenty minutes every few hundred kilometres against a chain and sprocket set every second year rather than twice a year. On a bike that is working for its living, that is not a hobby decision, it is the difference between a running cost you planned for and one you did not.