Suspension

Until recently, I have not experimented much with the suspension settings. The most I did was increase the preload a couple of rings at the front and add an extra couple of clicks on the compression damping. This was a bit of a compromise since when I was out blasting, the front would dive excessively under heavy braking and become a bit ‘wandery’ when really pinned down. If the preload / compression damping was increased to compensate, heavy braking in town just resulted in the front locking up too easily (I commute in London).

Now, I have another bike for going to work (Yam Div 600 – its shite!) and only really use the ‘9 on sunny days out of town. Hence, the desire to fiddle has come back.

This coincided with performance bikes doing a feature on the set up of a ZX9-R. They were only really interested in track use, but it gave me a starting point (see below).

I opted not to change the rear preload – no spanners and I felt it was hard enough as it was. It was an improvement (I think) but generally a too hard. It tended to skip over bumpy roads but was fine on good smooth tarmac – pretty much what you would expect for a bike set up for the circuit. I have pretty much backed everything off and currently run the following.

*  - C2 Model Set up for track use. C1 model has softer rear spring.
**- Dimensions are for static sag. 

I am weighing in at about 13st (in the scuddy).

This suits me much better. The dive from the front is much reduced under heavy breaking and has lost the wandering feeling as the weight is transferred forward. The back is still maybe a little hard, but I don’t want to back of the preload as this would reduce the rear ride height and slow the steering down (bear in mind that the increase in the front pre-load raised the front and also slowed the steering down). I find the bike hard enough to turn-in as it is (but good stability). All in all a definite improvement – a good compromise for bumpy B and smooth A roads. 

With the rear compression set at 10 from max, everything was fine until you carry a passenger (9 stone). The front is still ok, but the rear wallows. Previously when the rear compression was set at about 5 clicks from max, this didn't happen. So, I now run the rear at 7 clicks from max to give a reasonable compromise. Again, pretty much as you would expect since upping the compression damping has (in some conditions) the  'apparent' effect of increasing spring stiffness / preload.

Next was a set of shorter linkages for the rear. These raised the back end of the bike about 25mm and are available from Maxton at about £30+VAT. Dead easy to fit they are and it took about 1.5 hours by the time I had done all the faffing about. All you have to do is remove two bolts and replace the old with the new. Well, it would be easy if you can find someway of supporting the rear end of the bike without jacking off the swinging arm. In the end, there is a handy little bracket on the rhs that supports the bellypan. This, and the side stand, did the trick - a bit shaky though. Oh, one other thing - to save removing the exhaust, if you release the top shock mounting the lower linkage bolts will come out much easier.

And the result - much better. Its like the same bike and a new bike at the same time - if you know what I mean. You notice that it is higher as soon as you sit on it. It is a little heavier on the wrist as well.  It doesn't quite 'fall'   into corners, but it rolls over much quicker.  Stability doesn't really seem to have been affected. Mid corner and line holding are the same. I have been down some really bumpy roads and there has been virtually no head shaking (although I do tend to short shift a lot). Another bonus is the extra ground clearance - much less of the toe scrapping in the corners.

So far, I have covered about 400 solo miles and 130 two-up. My passenger immediately noticed the difference in height. So did I - after about an hour of slowish riding (40-80mph) things were pretty bad. Sore shoulders from the extra weight were the main problem. If my passenger was sliding about under braking before, things were much worse know. Still, it is a sportsbike, and so far, this is probably the best value mod I have done yet.

Update: I have now done about 2-3000 mls with the shorter linkages, and like everything else, you get used to the new position / extra weight on the hands. This is still an excellent low cost effective mod to the handling. Go buy some!!!!

I am also thinking about different springs for the front. Upping the preload is only a temporary measure of overcoming a week spring and I think stiffer springs on the front (Ohlins do a set 10% stiffer) is the way forward. Also, Maxton do a fork conversion, but currently have up to a 2 month waiting list!  And, if a rear shock doesn't prove too expensive (I expect £500) that will be next - one with ride height adjustment to get the thing turning even quicker and so I can back it off when I don't need it.. And then there is these lovely Harris rearsets and then...

Want to know more?