Tuesday Tip: Benchmarking Your Chain Adjustment

As your swingarm moves through the full range of suspension travel, your chain adjustment will actually range from slightly loose, to tight, and back to slightly loose again. The chain reaches its tightest point when there suspension is compressed so that there’s a straight line between the rear axle, swingarm pivot, and countershaft sprocket. That’s why you need to make sure your chain is adjusted correctly for that longest point, and once you’ve determined what the correct adjustment is, you can just measure it to duplicate it again.

Of course, when you buy a new bike is a good time to figure out that adjustment, and Spencer Bloomer from Kawasaki showed us how to do it.

  • With a felt tip pen, make marks at the center point of the rear axle and swingarm pivot.
  • With your bike on a work stand, loosen the rear axle and loop a tie-down around your silencer and the end of the swingarm. Cinch it down until you compress the suspension enough to create the straight line between those three points. You can check this by using the marks you created, along with a tape measure.
  • Once you’ve got the suspension set to the right height, adjust the chain so that it’s just snug. Roll the wheel to make sure it rolls smoothly. This is also a good time to check and see if you have any tight or loose spots (if you do it’s probably time for a new chain and sprockets).
  • Once you’ve got it adjusted correctly snug everything down. To ensure that the wheel is aligned correctly in swingarm, Spencer measures from the axle blocks to the rear of the swingarm.
  • Now you can slowly release the tie-down and remove it. Find a point on the swingarm (like the rear end of the chain buffer) that you can consistently use to measure from, and measure the resulting chain slack. That’s the measurement you’ll use from now on, and it’s far more effective than using the low-tech two or three finger method to check your chain slack. So…unless you have ironclad memory, write it down somewhere.