[twovalve]

Has anyone had any experience with head shake? Was on the 99 today with my 97 ZX9R, had just shed the cages, and was opening her up when, at exactly 150KPH (straight, mildly accelerating, not on a curve or braking) some pretty serious front end shaking began. Scaaaarrrry. :ghost Clamp and steering seem good....wondering if it's just the rim. Tight as todd at lower speeds, with nary a suggestion that it's lurking at the higher.

Any suggestions appreciated, except for Kawi=junk.

 

[Tattoodles]

This is the first symptom of worn steering head bearings.

 

[BMR]

And dirty underwear

 

[J1k]

balance the tire.

 

[LegalAlien]

I had the same happen too, a long time ago. But I was also due for a new front tire, so I don't exactly know if it was the new front tire, the balancing, or the combination of it, that solved the problem.

 

[bafflebrain]

This is the first symptom of worn steering head bearings.

Thats nonesense Adam. Everyone know Kawi are not designed to go over 150 Kph.

Keep it under 110Kph. Anything above that and you're committing an offense. :evilgrin

John is probably right - but also check your tire pressure. It could be low.

 

[twovalve]

Thanks, lads. Will check stuff tomorrow. I hate going over 150, but I have to shift out of 2nd sometime.....

 

[Bandit_Ryder]

Get a damper

 

[Team Green 9R]

wheel weights...stop ya from flying

 

[2xBlown]

Tight as Todd?

 

[twovalve]

I'm an English teacher in my other life and these quips just come to me. I now see the implications of the above and they are...er....a little off the intention. Apologies to the Todds out there. Was meant to be in the spirit as "right as rain", "good as gold", etc.

 

[michael]

May be a combination of all of the above mentioned:
1/ tire pressure
2/ steering head bearings
3/ tire wear
4/ tire brand
In own experience, on several differenct motorcycles, I found some tires brands are more prone to "head shake," than others, some appear when reaching a certain percentage of tire wear, some are sensitive to inflation pressures, and some are only steering head bearings.
One motorcycle only stopped "shaking it's head," when I got rid of it.....

 

[lowlife]

Get a damper

don't get a damper to FIX this problem, it will only cover it up, fix the problem first then buy the steering damper....dampers should be used like your leathers, you put them on and hope you never need them!!!!!!

 

[FiSh_Extreme]

Check your tire pressure first, if all is fine with that make sure your wheel is balanced or possibly bent.

 

[BlackScorpion]

Perhaps you travelled through some sort of a inter-dimensional portal or perhaps a hole in the fabric of our universe?

 

[jeckyll]

... and when you get a fix, pleast post up. Curious as to what the fix is.

FWIW, I've never had that problem on my 99 9R, but then again, 150 km/h, that's crazy fast

 

[identity-R]

Perhaps you travelled through some sort of a inter-dimensional portal or perhaps a hole in the fabric of our universe?

no no thats up past duffy there is none on hwy 99

 

[twovalve]

Bloody hell...so much for the quick fix. Pressure was low...raised it to 42 on 1/2 Pirelli. This time, around the same speed, it intermittently vibrated through to 170, though not as bad. I'm thinking the rim/balance next look. Had a stunning ride to Squamish and back though. Maybe the answer is to keep going faster. It worked for Yeager....

 

[jeckyll]

42? Are you shitting me?

What the hell are you running for tires? I run 34 / 36.

 

[SportBike West]

Had you adjusted your drive chain prior to this ride?

Believe it or not, a misaligned rear wheel, even only slightly, will do exactly what you describe.
All other suggested fixes: tire pressure, stem bearings, worn rubber will cause similar symptoms though not as pronounced as what you seem to describe. Stem bearings would cause a slow oscillation of the front end [ditto tires worn oddly] that gradually increases in frequency.
Sudden onset of front end wobble, I'd check rear wheel. 'course this is only my opinion and should not be used in place of getting service from your local motorcycle technician. Some would say I'm talk'n outta my ass.
Fair enough.
g'luck.