Head shake / high speed wobble

[PacerX]

So a couple of days ago I open the beast up for a full throttle blast and when I hit about 125, I get a high speed wobble out of the handlebars. I got a hold of it and settled it back down, but there was some serious pucker action. The whole bike seemed to be wobbling.

The bike was just serviced, has 4000 miles on it.

Any thoughts on why this would happen?

Bad tire?

Bad road?

Front end lifted under acceleration so the tire is skipping?

Think the steering dampener is shot?

It's never happened before, and I've been up over 125 on more than one occasion.

Any thoughts would be greatly appreciated.

 

[MoosesBusa]

I've heard of this on a few liter bikes from wrong suspension adjustments ( pre-loading the suspension too much ) and hitting some bumps during acceleration. Try searching for Jester's suspension thread and following those guidelines to set up your bike. That's all I can offer ya. I'm not an authority on bikes.

 

[Pipefighter248]

Few people on SH.org changed the fluid in the steering damper to help with headshake.
Putting in heavier oil seemed to help the problem.
They stated that factory oil is too thin.
I haven't tried this yet, am still debating.
Any thoughts about this?

 

[birdwah]

would this be the same i have problem over 40mph if you take your hands off the bars it starts to shake slightly but both of my buddies busas i can do it a 65mph with out a problem

 

[Lloyd]

Have you ever had it to that speed before? I assume you have..

 

[DREW]

check your tire pressures.

 

[#cruncherbusa]

Do you have aftermarket bar ends?

Possibly put on a new front tire?

 

[Busafied]

after a 90mph TS in the spring of '03 I made the change to mine..
never had a problem 1 outta the front since, period.

here it is laid out for you:

Tools needed:
6mm Allen wrench
14mm Socket
14mm open end wrench

Oil of YOUR choice, this is Tx, I chose to go to the Extreme

remove the dampner..
now remove the torx screw #10, #15 will work but keep alot of pressure on the driver, carefull !!! NOT to twist out the driver.

Cut a small watrer bottle top off, of soda bottle (plastic)..
Now, dry it out, completely..

Drain the oil out of the dampner as MUCH as possible, then fill bottle you cut with NEW thicker oil

Now, you think you got ALL the Air out of the Dampner???
Know how to tell???
Simple.. Move the shaft in the dampner, if it feels like you can easily move it side to side, in a short distance with NO resistance, YOU STILL HAVE AIR IN IT!

Do it AGAIN, till it is a COMPLETELY silk smooth, linear resistive force from one END to the other END of the shaft's travel.

Now re-install and ENJOY!

 

[HeliBusa]

If you have ridden the bike for some time at those speeds and not done any mods, I would bet more with tire pressure.

 

[rosco15]

My old Honda would headshake on me when the tire was old and cupped. Thats how I knew when to change it. I also had a friend get headshake at the track on his dragbike. It ended up being his front end was loose. Just some things to look at.

 

[PacerX]

Thanks gents! Lots of stuff to look into there!

I appreciate the help, and have some checking to do!


I checked tire pressures.

29 psi front, 32 psi rear, cold.

Bumped the front to 40 psi and the rear to 38 psi, we'll see if that took care of it. Next step is to take both to 42 psi should the need arise.

I'm a bit disappointed in the service department at the dealership given the numbers above, but I should know better and should have checked it myself earlier.

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[HillsRider]

If you have 4000 miles on the front tire & ran under 30 psi the whole time, I bet the tire is cupped. The busa is a heavy bike & can cup a tire very quickly. Just my $.02!

 

[schroetf]

why were you running 30 air pressure??

 

[PacerX]

why were you running 30 air pressure??

Well, honestly because the damned thing was serviced 200 miles ago and I expected the retards at the dealership to bring the tire pressure up to spec, thereby alleviating my responsibility for checking it until... say... 300 miles after it was serviced.

And, I was apparently wrong.

So, in the future, I shall check it religiously.


UPDATE: Went for a short ride, felt great to 115mph, I'll turn the wick up a little bit tomorrow and see what happens.



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[rahatsiz]

i used them ;front 42psi rear 42psi......
suspension setting is standart...
it jump after 270km/h
because of our roads... istanbul roads are very bad.....

change tires.. use pirelli dragon 190p... they solve your jumping problem...

 

[yello_ranger]

I got a 00 750 with a 02 1000 Motor....Dynos at 149 hp...If I hit the throttle hard, after going about 60-70 mph...the front end jumps off the ground about a few inches...and then the handle bars shake a few times...then front end comes back down...as soon as I shift and get back on the throttle again...the front end comes up and then shakes again...I have a new front tire and stock steering damper...I am looking to get either GPR,Scotts, or HyperPro Steering Damper to work with the stock...I am not sure if there are any settings that I could change to get rid of this shake...

 

[rahatsiz]

have you check your suspension settings??? are they standart..??

 

[rosco15]

A friend of mine on suday crashed his after a nasty head shake. New 05 with just over 100 miles. Took it to the strip. Rode a wheelie the 1/4 mile and crossed the stripe at just over 130. When he put it down it went straight into a nasty headshake and threw him off. I think I'm going to look into a good aftermarket dampner.

 

[05busa05busa05]

i'm not an expert but my experience has been a slight wobble when there is a crosswind.....of course i live in oklahoma where the wind blows non-stop.....this past weekend i experienced a wobble at about 125mph with a strong crosswind but later i hit 180 going down wind and it was smooth as silk....just one newbies experience.....my bike is a bone stock 05 LE.