If ever a thing deserved the description 'black art,' motorcycle suspension is it. Your bike’s suspension needs to suck up bumps, control fore and aft pitch, steer the front wheel, create traction at the rear … and do it all from straight up and down to leaned all the way over on the tires’ edges.
The basic concepts are easy enough: coil springs and compression damping determine how your suspension compresses. Rebound damping (and the same coil springs) determine how it uncompresses
. The rates at which those two things happen and under what conditions is the complicated part. All I know is that when your suspension is right, it’s good, and when it’s not, it’s often uncertain what is exactly to blame.
Paul Thede of Race Tech, a big suspension player, used to say 'the best you’ve ridden is the best you know,' and that’s exactly true. Some late-model bikes come really close right out of the box, I noted as I watched the shadow of myself rolling down a bumpy dirt road in Death Valley a couple of weeks ago: the KTM 1190 Adventure
’s tires were churning up and down like crazy, but you could barely tell from the saddle. If you’re trying to make that happen on an older machine, you might need a little help, and the fastest, cheapest way to get there in the end is to consult a specialist in the beginning. You might get there eventually on your own, but there’s something to be said for having a big database.