Used Bike Guide – Chain/Sprockets/Belts

Filed under: Buyers Guide |
  • Grab the chain at the rearmost point on the rear sprocket (warning: greasy!) and pull backwards. If you can pull it off the sprocket enough to expose half of a sprocket tooth (or more), it’s time for a new chain. £100 + an hour of labor to install. Some rust on the side plates of the chain is fine, but the rollers (the round middle part) should be shiny and smooth.
  • Sprocket teeth should be absolutely symmetrical — they’ll tend to get hooked as they wear. Look at some of the exposed teeth from the side to check the individual teeth for hooking. Don’t forget to check the front sprocket, too, if visible. (It’s often covered.) Hooked teeth = new sprockets. £60 total for two new sprockets, plus an hour or so to install.
  • If the chain uses a clip-type masterlink, make sure the clip is still present. (The clip slides over the pins that extend through the sideplate of the masterlink, and is designed to prevent the sideplate from sliding off the pins. They’re extremely common in aftermarket chains.) Make sure the closed end of the clip faces toward the direction that the chain rotates (otherwise it’s installed improperly and more likely to fall off.)

If the bike has a centerstand, put the bike in neutral, raise the rear wheel in the air, and you can check the chain condition. By spinning the rear wheel slowly (by hand, never with the engine), you can feel for tight spots and other problems.

  • Except, please, for goodness sake, don’t stick anything you care about (e.g., your fingers) near a moving chain — plenty of people can’t count to ten anymore because their fingers got mangled when they got pulled into a moving chain and sprockets. Same goes for belts and pulleys (discussed below): fingers and moving parts do not mix – keep them apart!
  • Spin the wheel a bit, stop it, check the chain for kinking or tight spots. Spin the wheel a bit more, repeat. Tight spots and kinked/frozen links probably indicate the need for a new chain. If the bike doesn’t have a centerstand and you’re feeling brave, put the side stand down and have someone lean the bike over so that the sidestand is holding the rear wheel off the ground. Then do the aforementioned test of chain smoothness.

Most riders tend to have their chain set too tightly, massively accelerating chain wear and adversely affecting suspension action. With your friend putting all his/her weight on the seat, the chain should have at LEAST an inch of play at the middle of the bottom of the loop.

In response to asking this page’s readers how to properly check and adjust drive belt tension (if the bike uses a belt for its final drive, as many Harley-Davidsons and Buells do), it seems that belt drive bikes should come with tension gagues in their toolkit, and that the owners manual for the bike will explain how to check the belt tension.