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All modern forks and shocks have Compression and Rebound adjustment. All shocks additionally have spring preload adjustability and even some conventional forks used for Dirt- Track bikes will have adjustable spring preload. So you vintage guys who are not totally vintage might get something out of this tech tip.
Here is your basic rule of race. If the track is fast and smooth, you and your bike should be too. Therefore, a stiffer, slower set up will help you as a rider to be smooth. If the track is rough, you want the suspension to be softer and move quicker over the bumps.
This is where those fancy clickers come into play. If your bike is moving around too much on a smooth track, you can increase the compression and/or rebound settings to slow the fork or shock movement (stiffen).
If your bike feels too harsh or you feel every bump on the track then you need to decrease your compression and/or rebound settings (soften).
I don’t always prescribe to the idea that you move them both (comp & reb) at the same time. It is something you as a rider have to get a feel for or just rely on your mechanic (our dads mostly) to see what your bike is doing. That way when he makes the changes and it was the wrong way you can blame him.
As a rider, it should be easy for you to feel if the fork is too stiff. You should be able to feel it through the handlebars and into your hands and arms. To feel the rear requires a good connection between your body (actually your butt) and the seat. This will tell you what is happening back there.
Keep in mind when you feel the hits to your arms or butt, is it at the beginning of the bump, at the end or after you hit the 3rd or 4th one? This will help you to determine which way to adjust your clickers.
If it were at the beginning of the bumps, I would speed up my compression (soften).
If it were at the end of the bump, I would slow down my rebound (stiffen).
If it were after 3 or 4 bumps, when you feel a hit I would quicken my rebound (soften)
Compression adjustments should be made in 4-5 click increments and rebound should only be 1-2 clicks. The rebound circuit has a much broader range of adjustment and each click makes a big change especially if you are in the 0-10 clicks out range. Unless of course you have one of latest versions of our Ride Height Adjusters with the superfine rebound adjuster…..hint hint.
Most current forks will have the compression adjuster on the top of the forks and rebound is at the bottom. All conversional forks (old style) and the early model inverted forks will have the compression at the bottom and rebound at the top. If you’re not sure, look in your manual or ask someone who works on suspension. I would say ask you buddy but nine times out of ten, he doesn’t know either. He’s not going to let on that he doesn’t know so he’ll tell you what he thinks and will make himself sound very convincing but in reality, you have a 50/50 shot of him being right.
The shock is a little more set in stone. The top of the shock body will have the compression adjuster and the bottom of the shock (attached to the moving shaft) will hold your rebound adjuster.
Most modern shocks will have a High-speed compression (nut) and a Low speed compression adjuster (screw). The low speed controls the majority of the damping but if your directional speed is greater then say 40mph and you hit a hole the shock shaft is going to be traveling fast enough to use the high speed circuit. So keep that in mind when you make your adjustments.
One other thing to take note of: On most shocks, the rebound circuit is also a compression circuit. Therefore, if you increase your rebound damping you are also increasing your compression damping and vice versa. If your not sure if your shock works this way I would ask your buddy and then flip a coin 6 times and take the best out of seven……or ask a suspension guy.
Specific settings will vary depending on spring rates, valving, and oil viscosity so I can’t tell you where you should be but normally 12 out on compression (about middle of range on most suspension) and 10 out on rebound (again about middle of range on most suspension) is a good place to start.
Good Luck at the Races!
Davey Durelle #58