Compression and rebound do not have a magic number like SAG does. You need to feel what the bike is doing and make adjustments to counteract it. If your springs are too weak, you can make it better, but not correct.
LACK OF COMPRESSION DAMPINING (FORK)
1) Front-end dive while on the brakes becomes excessive.
2) Rear end wants to come around when using front brakes.
3) Front suspension bottoms out with a solid hit under heavy braking.
4) Front end has a mushy and semi-vague feeling
TOO MUCH COMPRESSION DAMPING (FORK)
1) Overly harsh ride with the front wheel
2) Bumps are felt directly through the chassis instantly
3) Brake dive is reduced drastically though the chassis is upset by bumps during braking.
LACK OF REBOUND DAMPING (FORK)
1) Fork offers plush ride when riding straight up. But as speed is increased the feeling of contol is lost.
2) After hitting bumps at speed the front end tends to chatter or bounce.
3) When entering a corner at speed the bike will tend to wallow or porpoise before settling down.
4) As you increase speed, steering needs to be more aggressive and both chassis attitude and pitch becomes a real problem. You lose front end feed back after a hard countersteering turn.
TOO MUCH REBOUND DAMPING (FORK)
1) Ride is harsh
2) Under hard acceleration out of a corner the front end feels like it wants to "wiggle". And the tire feels it isn't staying in contact with the pavement when on the gas.
LACK OF COMPRESSION (REAR SHOCK)
1) Too much squat under acceleration and wants to steer wide exiting corners.
2) Hitting bumps at speed causes rear end to bottom
3) Chassis attitude affected too much by large dips and steering control becomes difficult.
TOO MUCH COMPRESSION DAMPING (REAR SHOCK)
1) Ride is harsh, but gets worst the faster you go
2) Harshness hurts rear tire traction over bumps, especially during acceleration.
3) There is very little rear end squat under acceleration
4) Bumps are felt directly through the chassis and when hit a speed, the rear end attempts to kick up.
LACK OF REBOUND DAMPING (REAR SHOCK)
1) Ride is plush at cruising speeds, but as speeds increase the chassis begins to wallow and weave.
2) Poor traction over bumps under hard acceleration.
3) Rear tire tries to chatter under hard acceleration.
4) Rear end can begin to pogo after hitting a bump
TOO MUCH REMOUND DAMPING (REAR SHOCK)
1) Very harsh ride with rear suspension action very poor with vague feeling
2) Poor traction over bumps during hard acceleration. Because of the lack of suspension action.
3) Bike wants to run wide in corners since rear is packed down, which forces a nose-high attitude.
4) Rear end wants to hop and skip when throttle is chopped during corner entries.
