How to Adjust Chain Tension on the 2008 KLR650

Issue: When changing the front sprocket on my 2008 KLR650 from 15 tooth to 16 tooth, I noticed that the chain tension was far too tight and needed adjustment.  I don’t think the excessive chain tension was due to the new sprocket.  I believe the chain tension was changed when I had the rear tire changed to the Kenda K761.  Note to self:  pay more attention to the chain tension and check it on a regular basis to prevent unnecessary wear and tear.

The specifications on chain slack measurement detailed on the swing arm of my 2008 KLR650 lists the range as 35-45mm from at the midpoint of the the swing arm.  The midpoint is determined by measuring from the center of the front sprocket to the center of the rear sprocket with the bike on its side stand.  Based on what I’ve observed and read on other blogs, I believe that the suggested range should be in the 45-55mm range.

Instructions: (see video below)

1. Measure to determine the midpoint on the swing arm and mark it with a Sharpie.
2. With a 12mm wrench I began to adjust the dog bone bolts that are located just in front of the rear axle.
3. Keep track of how many time you turn those bolts and make sure its even on both sides.  I lost track and one point and had to rely on the alignment marks and string method to ensure the rear tire is aligned.
4. After adjusting the the dog bones I loosened the rear axle and slid it forward to rest up against the adjusters.
5. Repeat the procedure above until you achieve the desired slack.  I choose to go with 45mm (with the 16 tooth sprocket installed) as I will be changing between the 15 tooth and 16 tooth sprockets and don’t want to constantly adjust the chain tension as well.
6. Make sure to tighten the dog bones and torque the rear axle.
7. Clean and grease your chain while you’re at it.

Note: Make sure to check you chain tension periodically as the slack can change over time with the wear of the sprockets and chain.  If the chain is too loose you run the risk of it jumping off the rear sprocket.  If it’s too tight you run the risk of prematurely wearing the shaft, chain, seal and sprockets.  I’ve had my chain on for over 12K on my KLR and it is still in great shape.