try going over a speed bump with th susp in the highest setting. all you hear is the shock about to fall out because nothing slows it down and it just hits hard. just by that observation i do not believe that they are variable because the bound shoud be slowed if it was. Bound is the opposite of rebound meaning the tire is going away from the fender. rebound is when the tire is going towards the fender. Just in case you were wondering.