Rebound Damping

 

Rebound damping ( I have seen Honda term it "tension damping) is probably the most misunderstood adjustment. The easy part is understanding what it does to the unit (it damps the rebound, or extending stroke) The strange thing is that many bikes only have one damping adjustment and rebound damping is it. So when many people just think damping they don't know which damping they are really talking about.

Rebound damping adjustments are easily felt: when you are going through a corner and the suspension bobs a bit you can slow down (increase) the rebound a click or two and it will go away. You can also control chassis pitch with rebound in the shock because the slower the shock extends the slower weight will be transferred to the front

There are problems with too much rebound damping. With too much rebound damping the suspension unit "packs down" or loses travel because the point of rebound damping is to slow the extension, and if you hit lots of bumps close together the unit doesn't get a chance to extend. Plus, with too much rebound damping the tire doesn't get back on the ground right away after a bump so there is a loss of traction.

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This wee little bike has too much rebound damping on the fork and especially on the rear (you can see the tire loses contact with the ground on the backside of the stair) it also has too much compression in the rear and not enough compression in the front (the rear doesn't give enough to keep the bike level, the front bounces up off the ground) but then again, that's probably not his favorite road.

Tankslappers can happen because of too much rebound damping in the fork. This is the chain of events: the tire hits a bump and goes up but is not returned fast enough to the ground for the second bump, without any weight on the tire for the second bump, the tire gets bounced, maybe to one side, and that starts an oscillation, and boopty boopty boo and your into a full on tankslapper.

My rule of thumb when it comes to any form of damping: use as little as possible, let the springs do the work!

Wheelspin. Another drawback to having too much rebound damping is that you get more wheelspin because as the tire is slowly lowered to the ground, the grip is too gradual and it starts to spin, and once spinning it is easy to keep on spinning.

Rebound damping and braking: If you find that your rear end "comes around" or gets "squirrelly" under hard braking, you probably have too much rebound damping in the shock.The problem is that the tire is not returning to the ground so it is just skipping along the high spots in the road.

Tidbit: rebound damping strength is usually 1/5 of the compression damping

 

Kevin Schwantz is best known for his work with suzuki.He started with Yoshimura on a GS750, then to the GSXR750. He won alot of races, but as one writer wrote," he stacks as many bikes against the fence as he does trophies on the shelf" he lost his ama championships as well as 3 world 500cc GP championships to arch rival Wayne Rainey due mainly to consistancy. Schwantz won the 500cc crown after Rainey was Paralysed in 1993. Schwantz was also one of the few american gp stars not to win the suzuka 8 hours race,but he did win the Daytona 200..Mick Doohan calls him the fastest man he raced against.