Motorcycle suspension setup can be confusing and downright scary, especially if you hope to figure it out on your own. Or you might wonder: Does it really make a difference in how my bike handles? The answer is, yes, it does.
Suspension is what keeps your wheels in contact with the road, your bike balanced, and your weight distributed in a way that’s optimal for the type of terrain you’re covering, whether it’s silky-smooth tarmac or gnarly off-road. Stock motorcycle suspension is typically set up for an average rider doing average roads, and let’s face it, that person just doesn’t exist. Everyone has a different weight, height, riding skills, the type of riding they do, and so on. Customizing your motorcycle’s suspension to your own needs is the biggest favor you can do to yourself as a rider.
Better yet, adjusting motorcycle suspension isn’t that scary once you know how to do it. Learning about motorcycle suspension tuning is the quickest way to get your motorcycle suspension setup perfectly for you.
How to adjust motorcycle suspension to your weight in 7 quick steps
If you already know what you’re doing and just need a quick reminder of how to adjust motorcycle suspension to your weight, here are the steps:
1. Check that all components are mechanically sound and there are no oil leaks
2. Lift the front wheel off the ground using the center or side stand. Measure the exposed part of the fork leg and write it down in millimeters as L1
3. Position the bike on the ground with the rider in full gear on it. Measure the exposed part of the fork. Write it down as L2
4. Calculate the sag, L1-L2. The sag should be about 1/3 to ¼ of the total suspension travel. Sport rider suspension settings usually have 30mm to 40mm rider sag.
5. Adjust the preload on the forks to achieve the suggested rider sag. More preload = less sag, less preload = more sag.
6. Do the same for the rear. Lift the rear wheel using the center or side stand. Measure between the axle and a distinctive point on the tail. Write it down in mm as L1. Put the rider in full gear on the bike, and measure the same distance to get L2. Your sag follows from L1-L2. Determine the ideal sag for your bike and riding requirements. Adjust the preload on the rear shock.
7. Set your compression and rebound damping for the front and rear.
These steps are easy to do if you’re already familiar with suspension tuning. If you’re just starting out and are hoping for a “motorcycle suspension setup for dummies” guide, fear not – we got you covered!
Let’s dive into the lingo of suspension adjustment first:
Sag is the distance the suspension compresses from a fully extended, unloaded position. This is the first thing you check and adjust when setting up your suspension. Free sag is the distance the suspension compresses under the weight of the bike alone. Rider sag is where the suspension settles with a fully geared-up rider on the bike.
Preload is how much the spring is compressed from its original length with the suspension component fully extended. Preload alters how much force it takes to initiate suspension motion. More preload makes the bike sit higher. More force will be needed to compress the spring, making it harder for the bike to bottom out. Less preload on the other hand makes the bike sit lower and closer to the bottom of its suspension travel. The main purpose of adjusting the preload is to set sag.
Damping means the reduction of the amplitude of a mechanical oscillation. On a motorcycle, damping regulates the extensions and compression speed of the suspension. When the suspension moves, the oil in the forks and rear shock gets pushed through a small hole or other restriction. The oil’s resistance to flowing through this restriction slows down the suspension motion.
Compression damping determines how fast the suspension can compress when you hit a bump. Rebound damping determines the speed at which the suspension extends after you’ve gone over a bump, to keep the wheels in contact with the road.
Spring rate is the spring’s stiffness in pounds/inches or kilograms/ millimeters. It describes how much force it takes to compress the spring at a given distance. Having the right spring rates for your body weight is important. Springs need to be soft enough to handle bumps, yet stiff enough to prevent bottoming out.