ZX6R rear shock adjustment

[Cossie]

Hi guys,

When I bought my 98 ZX6R the woman owner had the bike lowered. The front forks had been raised through the triple clamp and she said they had changed something on the back suspension. I've moved the front back to where it should be (actually the garage did when they did fork seals for the rwc)

The dogbones appear to be standard (185mm between hole centres).

With the height adjustment nuts on the top of the shock, should one nut be above and one below the frame where it attaches?

Because both the nuts are on the top, so the only way I can see to wind it up is to put packers in between the frame and the shock, or put one of the nuts under the frame and adjust it up, then lock both nuts tight against the frame? Does this sound right?

[Neka79]

sorry i cant really help... however... if u could get a pic of it... im sure sum1 here would have a similar bike to compare, or a user manual that may help...

give it a day or 2 for responses and all will be revealed..

oh.. welcome..

[Cossie]

Thanks Neka,

Yeah I probably shoulda introduced myself, first post and all, but I thought I'd try and sneak in un-noticed. Anyhow, obviously I ride a 98 ZX6R and its purely a commuter at the moment but I'm trying to find the time to get out on some 'proper' rides.

I've changed the setup to how I think it should be and gained 20mm in height at the rear.

Here's a pic of it now:




From the top, there is a large nut, then the bike frame, then a smaller nut, then 2 washers and then the shock.

Before, both nuts were on top of the frame and there was just one washer between the frame and the shock. I added the second washer just so the entire weight isn't relying on the threaded rod and I remember reading about it somewhere.


So can anyone see anything wrong with it this way?

[dave#3]

It looks good. I think you've raised your ride height by about 6mm above stock with the two washers, which won't do this bike any harm at all. More importantly, how does it feel?

[Cossie]

It feels like a brand new bike! I'm gonna have to learn to ride it all over again!

It tips in sooo much easier than before. it feels like someone has added an extra 20psi to each tyre! Much more responsive.

[dave#3]

It feels like a brand new bike! I'm gonna have to learn to ride it all over again!

It tips in sooo much easier than before. it feels like someone has added an extra 20psi to each tyre! Much more responsive.

Perfect. Once you get comfortable with the way it is now add another washer and see if it's even better or if it becomes unstable. Keep adding washers until you think it's not stable then remove 1 or 2.

[Strika]

There is a magic number where that bike will work. Adding washers can aid turn in, however, too many will make the bike not just unstable as others have suggested, but it will also understeer at full lean. It's also not just a matter of rear ride height, but more height and steering head angle. If you really want it to steer nicely, some might say to aim for around 24 degrees then play with front and rear ride heights evenly until you are happy. Just maintain 24 degrees head angle, unless you intend altering the offset of the triple clamps or swingarm pivot or length.

[Cossie]

Thanks guys,

So has anyone done much experimenting to see what the 'magic number' is? ie is 2 washers too much, or somewhere in the right region? The front height is standard now.

[zenodamper]

Mmm, something to help with... 4-6mm should be about right...

Don't forget the height at the rear is 1/5 for turning-in, but 4/5s for turning out - though I have always felt it to be more close to 2/5s, 3/5s; but there you go...
Anyways, adding too much rear height is nice for getting out of turns on a nice tight line; but if the fork will not take it (captain), then it will go weird at mid-corner (like el Strika mentioned). And the G model's fork springs ain't the stiffest on the planet.... Still, all that said, the fact that the model has rebound flaws in the cartridge (fork), by having more weight on the wheel, will at least aid and abet some of the washing-out sensation (springs releasing energy willy-nilly) - though it is a double edged sword with too weak a spring, and likely leads to a fine balance between the extra preload needed to get sag, and the rebound not available to control the pre-tensioned springs....

Did not the J models have the twin nut arrangement to allow for height adjustment? So perhaps the previous owners had just put them both on top in order to get the bike lower?

Good luck in either case...

[Cossie]

Thanks zenodamper. Probably a bit more involved than I need to go for a bike that spends most of its life lanesplitting! At least I know it's something like where it should be, just got to find some twisties to test it out a bit better!

[Slow and wobbly]

Did not the J models have the twin nut arrangement to allow for height adjustment? So perhaps the previous owners had just put them both on top in order to get the bike lower?

Good luck in either case...

Take the washers out and put a nut underneath and retain the one on top. By just using the washers you will get movement and cause elongation of the hole which the mount passes through. Put a washer underneath each nut on the load side. By adjusting the nut on the underside you can alter the ride height while the top nut is a lock. Clamping the nuts together from either side will ensure it is working as it was designed to. Dont forget to replace the split pin at top too.

[Cossie]

There is a nut on the bottom.

[belair]

I put 3 washers in straight away, in the end it was an 11mm increase in height i think. Works pretty well but wouldnt want anymore added height. Heres the end result:

[IrishPete]

Er, is the lower nut not there specifically for ride height adjustment?

Can you not just wind that up to change the rear ride height instead of sticking a bunch of washers in there?