a bit unstable at higher speeds

Might want to make sure the bearings on the front end - axle, steering, etc - are all good. It could very well be the combined forces of the wind knocking you around enough to create unintended steering inputs.

A steering damper might help, but I'd check the bearings first. If the previous owner (was there a previous owner?) did a lot of wheelies and such, it could have messed the bearings up.

+1^^ Check the bearings first. Either way a damper can't hurt anyways!

nice to know your name ,ben didn't notice it before. anyway i've logged over 45,000 miles on zrxes since 03. both of mine were unstable at about 120mph and above. didn't go over that only about 3 or 4 times. son had a vfr800 modded both would show 155 on speedo. i know they are off. i think that may be why they limit speeds on most naked bikes to btween 130 and 150mph. don't remember conversion. also my son check air in his new zx10r because it handled worse than his harley. 10lbs. front 30lbs rear. just sayin.

It could definitely be an aerodynamic thing - air kicking you around or whackin' the bike around. I don't spend much time up that high ever, so I don't know if mine does it or not. I'll have to give it a try...

Thanks to all.
I don't think this can be bearings since i bought the bike as factory new with 0 mileage, it was a demo bike or something. Bought it in may this year. I'll put the damper and replace those stock mirrors with smaller bar end ones, i'll see if there's any improvement.
Thanks again

try sliding back on seat, is the dampening to hard?

also streeet, if you are to tense because of the wind your ride will be a hard on.

no doubt a street fighter is not going to cut the wind over 100 mph. i only do a quick blast up to that speed once in a while. so for me no problem. i did have my ZRX up to 135 one time and it was ok, ran out of room to go faster.

I reached over 240km/h with my 93 Suzuki rf600 r, and it felt like cruising speed, but i was fully tucked in. I've also seen on u-tube, one guy doing 275 km/h on an 03 Z1000, thats why i was surprised when my bike got a bit twitchy at 150. But now i think its just part of the whole joy of riding a naked bike .

that sounds mighty fast.anyone know how to change that to mph.

Divide the km/h by 1.6. The result is mp/h 240 is some 150mp/h

Handling of the bike improved a lot after i put the new handlebar. Pushed it to 220 km/h and i didn't feel any wobble. Was surprised that there would be such an improvement

had a wobble about 120. my uncle noticed my back tire was a little off center. straightened it up. and it went away.appeared like the chain side moved forward, as i know they were even when i changed tire. maybe too much wrist.

170 mph smooth as glass

what gearing are you using? or whose bike are you riding?

I got mine to 150mph and ran out of gear, probably because it's +3 in the back. I wouldn't say it was wobbly or unstable, but it was definitely white knuckle for a bit. Just because, at those speeds, on the country road I was riding down, a deer could've jumped out 100' in front of me and all I would've been able to do is close my eyes and brace for the splat.

I guess I'm not even sure what unstable is though because my Z is the first bike I've ridden over 120 mph. My previous, and first bike, was a 1977 CB750F. You want to talk about unstable at high speeds, try tucking behind a 7" headlight and putting your feet on the passenger pegs on a 30 some year old bike just to see what she still has left in her. After that bike, my Z feels as smooth as glass.