Preload or rebound damping

When carrying a pillion on the GSX-R 1000 and mid corner, things have started to get a bit bouncy at the rear…That’s not the pillion’s ass, but the rear suspension of the bike.

I haven’t yet added some pre-load to compensate for the added weight of a passenger, but I’ve started wondering whether a bit of rebound damping is the order after reading a very good book called, ‘Sportsbike Suspension Tuning’.

In the troubleshooting section, where the symptoms are unsettled wobbly suspension mid corner, it says to add rebound damping, but this is based on a single rider.

I’m going to experiment with a few settings, but wondered if anyone out there had come across a similar situation.


If its getting a bit bouncy then you may want to increase your rebound damping a tad:cool:

From other experience of tuning suspension, if it’s an easily accessible control, try testing different settings. Try making it alot slower, then back it off faster to fine tune. Often a novice tuner will struggle to ‘see’ the difference in a setting without experimenting widely. Then use fine tuning to get it right. If its hard to access twiddle it abit and pretend you know what your doing :stuck_out_tongue:

The preload dictates where in the suspension the bike sits when loaded (it’s sag), and how far it moved for a given force.
The compression damping sets how fast the suspension moves through it’s travel for the above given force.
The rebound damping sets how fast it returns to the original (sag) position.

If the bike is sitting very low in the travel, you need to adjust the preload, since this sets where in the travel it sits.
If the bike is moving too quickly through what’s left of the travel, you need to adjust the damping.

In general, you’ll set the preload up first and while the bike is static. You know how far through the travel it should be, so you just twist the collar until it’s about there (with your given load on it). If you get the preload right at the beginning, you’re less likely to find yourself trying to cure preload problems by adjusting the compression damping (increasing the compression damping can feel like the preload’s been increased). Also changing the preload generally affects the rebound and compression damping, because of what it does to the springs, so you might as well do the one that’s easy to measure as correct first.

Measure each of your adjustments, so you know where to go back to when another four clicks or quater of a turn or something feels less good than before. If you’ve got both rebound and compression damping adjusment, one being way out can make it feel like the other is.

Hey Chunky…Why would one fork leg have less rebound adjustment than the other :unsure:

The left leg allows 14 clicks out from stiffest, but the right leg only allows around 9.

Is the leg damaged?

Probably got gravel in it mate;):smiley:

Seriously, I’ve no idea. All mine have been symetrical IIRC

Funny guy…This is on the GSX-R :slight_smile:

Cheers mate…I’m gonna get it checked out.

The rebound increase has made an improvement btw :cool:

I would add a bit of compression damping to compensate for the extra weight pushing down on the shock over bumps - having extra weight should have a similar effect to additional rebound damping. If you slow the compression down it should not spring back as much either.

Doesn’t sound right, but I know there were a few people a couple of years ago that experimented with high speed and low speed damping in separate fork legs. Do you know if the previous owner fiddled with it?

That don’t sound right at all Afro!

I only really know about suspension from mountain biking, but there too we have preload, compression and rebound damping - essentially its the same technology and you shouldn’t have 2 different stanchions giving 2 different distances. Are you 100% sure that the right leg is at its stiffest before you start the turns?

You might be right there Et. There was a lot of talk about that at the time.

Not sure how you’d check apart from comparing the shim stacks etc.

spring preload is what you change when carrying a pillion , best not to change the rebound and compression damping neither will help the extra weight , rebound is the most critical as it can make the rear tyre loose grip as the wheel dosn’t react fast enough to the bumps , a chopped up rear tyre is a sign of too much rebound damping

It’s a given that 'Fro understands that the preload need upping. What he asked was how to settle down the pogo stick effect;)If you want to be pedantic you might argue that adding preload is a waste of time. What you need in theory is a stronger spring:cool:

This is the second time I have heard this about GSXR thous. Not the best for pillions it seems - not sure how much fiddling will be able to fix it.

Thanks for the advice everyone.

Well I spoke to Brian about this yesterday, and he said that since both settings are made by winding out from fully stiff, it doesn’t really matter if the number of clicks aren’t the same when wound fully out. They should be the same setting.

What I’m worried about though is that the fork without the same adjustment range, does indeed have more range, but there is something stopping that adjustment from being made.

What I’m saying…Although the leg can’t be wound in past its stiffest…It isn’t really at its stiffest setting.

I’m going to get the fork oil changed whilst they sort out the fork leg which is leaking again…This isn’t the shock with the limited adjustment range by the way.

Whilst they change the oil, I’ll ask them to examine the adjusters.

See what they say.

Not at all mate. The bike is the best sports bikes I’ve ever carried a pillion on. Much better than the R1 or R6 as the pillion seat has more foam and the pegs are more relaxed.

Still, there will always be compromises as these bikes are designed for a single rider weighing around 160 pounds.

Remember that time I had Tony on the back of the ZX6R? I hardly felt he was there (apart from that pistol he had in his pocket) until he almost fell of the back when I inadvertently pulled that wheelie in the limehouse link.


That was a classic :smiley:

I remember your look of panic followed by the hysterical laughter…Was a pretty decent wheelie actually.

Gotta learn how to do them myself…I’m learning clutch ups and am at the stage of the front wheel just bobbing up a little bit…Need more revs…Need bigger bowals :smiley: