Suspension setup can be the difference between a good day and a bad day out on the trail. We asked Torpedo7 MX rider Simon Lansdaal to share some of his advice on write up a quick suspension tuning guide to help you get the best out of your ride.
Many people underestimate the value of a correctly set up bike and it is easy to overlook the benefits of spending some time to set the suspension to what is required for your size and riding ability. The right suspension for you and the bike can make riding safer, easier, and a whole lot more fun!
Before you spend time setting up your suspension make sure your steering head and linkage bearings are running free. This can have a massive effect on how your suspension works. Also check that your suspension isn’t in need of a service, it is recommended that you service suspension every 40 hours. It’s not uncommon to overlook and neglect suspension but a good service and some fresh grease in the bearings could make a massive improvement on your bikes handling. I recommend getting an experienced suspension tuner to service suspension.
When your bearings are running free, next you should check the shock preload or race sag. If you have too much race sag the back of the bike can feel low and can cause the rear suspension to feel harsh and not enough race sag can cause your bike to be hard to turn and climb out of ruts. Some bikes may require a different sag setting e g. KTM with pds rear shock, so check your manual before making any changes.
Race sag should be one third of your bikes rear suspension travel, on most full size bikes that works out to be between 100 and 110mm.To measure sag place motorcycle on a stand so the back wheel is off the ground use a tape measure and measure from your axle to a mark on your rear fender (it doesn’t matter where you measure to as long as you measure to that same point every time). Take the bike off the stand and park near a wall. Sit on the bike in a neutral position with feet on the pegs (lean your elbow against a wall to maintain balance). Bounce up and down a couple times and let your suspension settle. Get a buddy to measure from the axle back up to the same point on the rear mudguard. Race sag is the difference between the measurements (measurement with bike on the stand minus the measurement with you on the bike). For example if your measurement on the stand is 640 and the measurement with you sitting on the bike is 525 you have 115mm race sag (640-525=115). You will need to adjust and re check until correct sag is achieved.
To adjust the sag place your bike on a stand so the back wheel is off the ground and undo the locking nut on top of the spring. Wind the spring anticlockwise to increase sag and clockwise to decrease sag. Make sure to tighten the locking screw when sag is set correctly. After the correct race sag is set check your static sag. Static sag is a measurement of how much the bike sags under its own weight. Static sag can only be checked after race sag is set. Place motorcycle on the ground, bounce the suspension a couple times, let it settle and measure from the axle back up to the same point on the rear mudguard. Static sag should be between 30mm and 40mm on full size bikes. If you have more than 40mm of static sag, your shock spring is too stiff. Less than 30mm and your spring is too soft.
Clickers are a good way to fine tune your suspension. Most bikes will have about 24 “clicks” of compression and rebound adjustment on the front forks, and the same on the rear. Usually the rear shock has high speed compression adjustment also. Check your manual as this can change from bike to bike. Compression adjustment affects how fast the fork or shock compresses, and rebound affects how fast the fork and shock rebounds back after an impact. High speed compression effects how the rear shock absorbs square edge bumps, high speed doesn’t refer to how fast the bike is traveling but refers to how fast the shock has to react.
The most common mistake of setting up suspension is making it softer when it needs to be made firmer. Forks that are too soft dive excessively under deceleration and ride on the firmest part of the fork’s damping. This makes them feel stiff. When the rider notices how stiff his forks feel, he naturally turns the clickers out to soften the forks. This obviously makes the situation worse. Forks that are too soft feel stiff — when in reality, they need to be stiffer to feel softer. Make sure you keep notes on every change you make, whether it’s an improvement or not. It’s easy to make it worse and you want to be able to go back to previous settings if needed.
It’s important to bleed the built up air from your forks every time you ride. Air pressure builds up under normal use the more air in the forks, the stiffer they will feel. To bleed the air out of your forks, you need to make sure that the front wheel is off the ground and that the forks have completely cooled off. Open the bleed screw and let the air bleed out (you should hear a little hiss as the air escapes).
Fork air screw is located on the top of each fork leg compression adjustment is usually located on top of each fork leg also. Rebound is usually located on the bottom of the fork leg under a rubber cap however on my WP 4CS forks I have compression adjustment on the top of the left fork and rebound adjustment on the top of the right fork so check you’re manual if you’re not sure.
Modern bikes come set up from the factory for the “average” rider (average weight and speed). You may need stiffer or softer springs and possibly a revalve. If you are outside of what your bike is set up for, all the clicker changes still won’t make your bike handle its best. If you are struggling with your set up there are a number of suspension tuners that can help you out. A full front and rear Revalve usually cost about $500, and a set of springs retails for $350 to $500. It may seem like a lot of money but a correctly set up bike will be faster, safer, easier to ride, less fatiguing and get more traction. A good suspension set up will make a much bigger improvement than a flash exhaust or shiny triple clamps.
To follow Simon keep an eye on his Facebook page.