KAWASAKI ZXR750H1 SUSSPENTION PROBLEMS

[Johan]

I have a ZXR750H1 1991 model KAWASAKI with a susspention problem.It's bouncing my lungs out and it feels rock hard at the rear.I've tried adjusting the rear susspention,butt no succes.Tyre pressure - ok.Rear shock not leaking and the rear wheel bearings are fine. Maybe I'm doing something wrong. Please help.The Bikes handling is really

[Finglonga]

Long shot ...check your chain isn't too tight as that would restrict the swingarms movement and bend your output shaft.
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Andy Sez....
F.Y.Y.F.F.

[Big Pete]

the early zxr750s were notorious for having a rock hard spring, so much so that Kawasaki released a softer spring for them. Alternatively NWS Performance IIRC made a new shock linkage which cured the problem completely.
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GarageOfPower.co.uk

[MarJay]

its a 1990's Kawasaki, they are all like that sir!

I'm serious - ZXR750's are really bad for rear suspension. Methinks that kawasaki got their calculations wrong with their spring rates and suspension linkage. Your best bet is to get the shock resprung, you might as well get it revalved whilst you are at it.

Try Race Components:www.race-components.co.uk
Maxton Engineering:https://www.esling.btinternet.co.uk/maxton/

Or a slightly more budget replacement shock : https://www.hagon-shocks.co.uk/main1st.htm

I had the same problem on my Daytona. The bike would have been OK if a normal sized person had ridden it, but being that I am only small I was not having the desired effect on the shock. I got race components to respring and revalve the shock, and revalve the forks and the transformation is amazing. You probably don't need to go that far TBH.

You might also try a hyperpro spring from PDQ : https://www.pdq1.co.uk/

If the rest of the suspension is OK then the Hyperpro spring is probably your best bet, but fitting it yourself is quite fiddly afaik. I think a single hyperpro shock spring costs about £50 ish. I believe that PDQ will fit the spring for you if you want, but I guess that depends on how close to them you live.

{edit} or you can go for a new linkage as Big Pete suggests, I know that NWS are very good, but I didn't know that they did ZXR linkages, my experience with them is mainly Triumph related!{edit}
Hope this helps!
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Kickstart]

Hi

I remember the NWS linkage as well. The ZXR750H* were notorious for the solid rear suspension.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Big Pete]

NWS are on 01992 501285 HTH
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Trust me, I`m an engineer
GarageOfPower.co.uk

[Johan]

Thanks for all your help, I do appreciate it .You guys probably saved me allot of money.Strange enough I was at the local race track on monday and saw a zxr750 with a aprilia rs250 swing arm and mono shock,it also lifts the rear about 6 inches higher.Spares are very expensive in South Africa and hard to come by.Most of our spares are imported from Japan.I am going to try the local agents and see if the Hyper pro spring is available ,then I will take it from there .I might consider the aprilia conversion ,but it looks like allot of work and I'm not so sure that it will work