Motorcycle Repair: How to adjust the rear suspension preload on a 2009 Kawasaki KLR650
**Always follow the instructions in your repair manual when doing repair or maintenance work on a motorcycle. Manuals can be found at the dealer and online.**
Rear suspension preload is how far the motorcycle drops due to the rear suspension compressing when the rider is on the motorcycle. This drop effects the bikes geometry, which effects the performance and safety of the motorcycle. The bikes geometry change from preload can effect the bikes ground clearance, steering geometry and direction of the bikes headlight beam. The rear shock on the 2009 Kawasaki KLR650 has 5 preload settings, and each setting is labeled 1-5. The settings are changed by rotating a bolt clockwise, and the bolt is located on top of the rear shock on the left side of the motorcycle. Kawasaki recommends the #1 preload setting for a 150 pound rider, but doesn’t give any further instructions for setting the preload for heavier riders.
As a general rule of thumb the rear suspension preload should be 25-33 percent of the rear suspension travel. On the 2009 Kawasaki KLR650 the rear suspension travel is 7.3 inches, so the preload should be set so the bike drops 1.8 inches to 2.4 inches with the rider on the motorcycle. To measure the preload, pick a point on the back of the motorcycle that is part of the bikes un-sprung weight. For example, any point on the swing arm works good. Next, pick a point on the rear of the motorcycle that is part of the motorcycle sprung weight. For the 2009 Kawasaki KLR650 I chose the helmet lock. Next, raise the motorcycle off the ground so the rear wheel is off the ground, and measure the distance between the two points. Record the measurement. Now take the motorcycle off the lift and have the rider get on the motorcycle, so the rider and motorcycle are in a natural riding position, and measure the distance between the two points. The difference between the two measurements is the rear suspension preload. With the 2009 Kawasaki KLR650 the difference between the two measurements should be 1.8 – 2.4 inches. If the difference is larger, than increase the preload on the rear shock, by rotating the adjustment bolt clockwise. The highest setting is 5, so if 5 doesn’t correct the problem, than you need a new rear shock with a stiffer spring.