let's talk about Rebound...
Posted by Tim McArthur on
Rebound is probably one of the worst understood factors in Road Race suspension setup. I commonly hear from riders that think they understand it, saying things like 'I like to have the front rebound a lot slower, so it holds the front down in the corner as/after I let go of the brake'
In short, this is wrong! It may feel as though that's happening, and will possibly work better than the previous setting, BUT this is simply a band aid over the real problem. What's really happening is; while the fork is 'holding down', around 90% of the load is still coming off it compared to before, but instead of it unloading the fork... it's now unloading the tyre! Initially this may feel OK, because when we ride we feel the load on the front via feel from the forks more than the tyre. The problem though, is as you get faster and release more brake more quickly, the load comes off the tyre more suddenly and you crash often on brake release, with no idea why, because the bike 'feels good' and it just 'fell over!' (obviously that's because at full lean, with no front grip... the bike WILL literally fall over!)
Te real problem in this instance, is what I call dynamic geometry (which means that the bikes geometry at that moment in time in the corner) is not right. In this case the dynamic geometry has the front too high / not enough load on it. This could be a variety of issues such as fork springs, fork preload, oil height, fork height in the clamps, valving, compression adjuster, rear ride height, rear preload etc etc.
These perceived shortcuts in bike setup, just move the problem to later, and cost a lot in the long run!
After this you're probably thinking of making your rebound really fast so this doesn't happen... but it's a balance! Rebound damping gives the bike stability while also managing grip, when set right. A well setup bike is not only fast and effortless in comparison... but a lot safer too!
To learn more about your own bike setup, get in touch with Tim, to book an at the track session, to get your bike (and possibly even your riding) sorted!