Steering wobble

[jrsndman]

I have been experiencing a wobble in the front end of my 2002 roadster. It happens under hard acceleration or at high speeds. I'm thinking it could be a combination of worn suspension and/or steering bearings.

I've had the bike a little over a year and put 4,000 miles on it. I've never ridden another roadster to compare it to so I'm not sure how normal this is. The bike now has 26,000 miles with the stock suspension.

Any thoughts would be greatly appreciated.


Thanks,

Jim

[Buckster]

It may be time to get new tires too. I started to feel a Slight wobble when my front tire was at it's end of its tread life.

[gregor]

I've had a wobble when I hit , I think, 90mph at the red line in 4th! I put that down to over enthusiasm, the MRA screen and the front end 'going light' over a crest.
I agree,Worn tyres are indeed the major cause of tyre wobble. But non standard windscreen and heavy luggage etc may contribute.

[MikeCam]

Tires first. Air pressure and tread wear, then balance. Also, consider the roads where this happened - everywhere or a particular road surface?
Next, is the wheel true in the forks? There is a procedure in the manual to do this right. Often skipped.
Third, shocks - they are good for about 24-28K depending on the rider and the ride.
Least likely is steering head bearings unless the forks have been worked on, modified, or damaged. Just doesn't happen on these models.

[jrsndman]

I attributed this behavior to worn tires too, until I put new Pilot Road 2's about 700 miles ago. No change in the wobble. The front wheel was true in the forks when I put it back on with the new tire, I'll check it again to make sure it still is.

I rode last night without the bags on and it had the same wobble so I'm sure its not the luggage causing this.

[CycleRob]

Also check the engine to frame mount bolts. All of them. The swingarm and FD pivot bearings are the most likely source as they are the most easily damaged from rain water, wash water and silty road water entry. A 7 year old bike gives all those possibles time to brew and work on eating away the tight clearances. Bike on the centerstand, from the right side grab the rear wheel at the very back of the bike and move it toward/away from you to check for play. It should have ZERO play.

Steering stem bearings failing would be a rarity as both are well sealed very heavy duty parts, but you can check that with 2 assistants:
Guy1--Sits on bike at balance point, squeezing the front brake.
Guy2--Grabs rear handrails (or front handlebars) poised to push the bike forward and backward.
Guy3--Holds one hand on lower bearing's connected parts and the other hand between the top triple tree and the frame - - - concentrating on any of the 4 components lateral movement as bike is being yanked forward/backward. Ignore any clunks or thumps from the brake pads. Movement is what Guy3 guy is looking for.

Front and rear wheel bearings need the 2 handed deflection test for play. There should be ZERO play.

A big windscreen can cause this too, but don't dismiss it because it hasn't done so before. Loss of support bracket strength can change it's behavior and affect the handling under conditions you describe.

.

[jrsndman]

I've checked all of the things listed above by CycleRob, they all appear to be in good shape. The more I thought about it the PIAA 910's I have mounted from the headlight bolts compound the problem at high speeds.
I figure I have three options:
a) relocate the 910's (I'm really happy with them where they are now)
b) add a steering damper (expensive)
c) ride another bike when I want excessive speed (simple solution)


I'll have the chance to ride another roadster this weekend to compare against mine and see if it acts the same.

[Ritchard]

I'll have the chance to ride another roadster this weekend to compare against mine and see if it acts the same.

What was the outcome? I had some slight wobble at rather irresponsible speeds a few weeks ago, was wondering what it was about.

[Sunbeemer]

I notice some wobble at great speed when my rear tire is nearly worn out, which became more noticeable after I installed a high seat, which I think raises my torso into the airstream causing the nose of the bike to pitch up. Upon the recommendations of knowledgeble members of this board, I raised the rear suspension by ~ 6 turns which helped quite a bit... The problem completely disappeared after replacing the rear tire.

[lee_davis_d]

Hi All,

It is probably tire cupping. Tires on bike wear unevenly. I noticed this wobble at 85 MPH on the bike with 6K on the front tire.

[jrsndman]

I'll have the chance to ride another roadster this weekend to compare against mine and see if it acts the same.

What was the outcome? I had some slight wobble at rather irresponsible speeds a few weeks ago, was wondering what it was about.

I rode the other roadster and determined that my problem is most likely suspension related. I increased the preload on the rear shock quite a few turns and it helped a lot. I would like to replace the stock shocks soon with Wilburs or Ohlins but can't spend the $$$ right now. Maybe in a few months.