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BMW c650gt front wobble vibration
- Thread starter Bojan Gjoshevski
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Bojan Gjoshevski
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Bojan Gjoshevski
Member
This is the rear wheel on the center stand.
Kiss4u
Member
From my point of view and from the evidence (photos and videos), the shoulder of your tire on the rim is good.
There's just an optical effect linked to the marks/dirt on the tire. But your rear tire runs smoothly and as well as you'd expect!
Have you explored the possibility of a foreign body in the tire (e.g. mounting residue) that could be causing a random imbalance? If I were you, I'd use a static hand balancer to check your two wheels on this and other points.
Wheel axle misalignment (usually caused by impact: potholes, kerbs, front or rear impacts) can also lead to shimmy.
On the front wheel, this can be seen immediately when the wheel is turned with a workshop stand to keep the fork upright.
On the rear wheel, if the axle was misaligned, this would be immediately apparent when turning the wheel with the scooter on the center stand. Not so in your case. On the other hand, if the swingarm axle was bent, it wouldn't be noticeable under these control conditions.
For the front end, I also encourage you to check the lateral AND axial play of the steering. Also check fork tubes for tightness and evenness of tube insertion heights at the fork tees.
For the rear, I encourage you to check the swingarm axle bearings and the straightness of the axle itself.
Finally, if there's nothing else obvious, I'd check the condition of the transmission and, last but not least, the tightening torques of the frame/motor rigidity assemblies.
There's just an optical effect linked to the marks/dirt on the tire. But your rear tire runs smoothly and as well as you'd expect!
Have you explored the possibility of a foreign body in the tire (e.g. mounting residue) that could be causing a random imbalance? If I were you, I'd use a static hand balancer to check your two wheels on this and other points.
Wheel axle misalignment (usually caused by impact: potholes, kerbs, front or rear impacts) can also lead to shimmy.
On the front wheel, this can be seen immediately when the wheel is turned with a workshop stand to keep the fork upright.
On the rear wheel, if the axle was misaligned, this would be immediately apparent when turning the wheel with the scooter on the center stand. Not so in your case. On the other hand, if the swingarm axle was bent, it wouldn't be noticeable under these control conditions.
For the front end, I also encourage you to check the lateral AND axial play of the steering. Also check fork tubes for tightness and evenness of tube insertion heights at the fork tees.
For the rear, I encourage you to check the swingarm axle bearings and the straightness of the axle itself.
Finally, if there's nothing else obvious, I'd check the condition of the transmission and, last but not least, the tightening torques of the frame/motor rigidity assemblies.
Last edited:
RollaCosta
Active member
Your frame may have been in an accident, and something is bent (front fork?).
Either that or steering column bearings. Perhaps time to check chassis geometry scrupulously?
Either that or steering column bearings. Perhaps time to check chassis geometry scrupulously?
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Bojan Gjoshevski
Member
Thanks,
Everything was checked at BMW dealership and they said the motorcycle is in perfect condition. Now I’m waiting on Michelin to send new tires and see if the tires were the issue. I still suspect the steering head beatings or torque. At the shop they did some tests, rode the bike and said that if the steering bearing was the problem the bike would wobble up and down.
I personally feel the handle bars a bit loose when I ride in slow speed.
I’ll post updates.
Ben
Kiss4u
Member
Good evening,
I doubt that the tires are to blame for two reasons:
1. Tires are inspected (molding, pressure and balance) by the manufacturer (Michelin) before being made available for sale, and in the event of a defect they are withdrawn. This is one of the most rigorous sectors in terms of quality, and the chances of finding a defective new tire for sale are almost impossible.
2. Your problem existed before the tire was replaced.
Your doubt about the steering bearings or something similar in the fork is very consistent.
In particular, the behavior improves when you brake (if the tire were defective, it wouldn't make any difference). In the braking phase, the mass transfer to the front axle may well develop sufficient force to block the play in a steering bearing and thus make the wobbling disappear).
Having said that, I'm not sure about your dealer's goodwill. A bike that wobbles is not a bike in perfect condition!
Good luck for the next step!
I doubt that the tires are to blame for two reasons:
1. Tires are inspected (molding, pressure and balance) by the manufacturer (Michelin) before being made available for sale, and in the event of a defect they are withdrawn. This is one of the most rigorous sectors in terms of quality, and the chances of finding a defective new tire for sale are almost impossible.
2. Your problem existed before the tire was replaced.
Your doubt about the steering bearings or something similar in the fork is very consistent.
In particular, the behavior improves when you brake (if the tire were defective, it wouldn't make any difference). In the braking phase, the mass transfer to the front axle may well develop sufficient force to block the play in a steering bearing and thus make the wobbling disappear).
Having said that, I'm not sure about your dealer's goodwill. A bike that wobbles is not a bike in perfect condition!
Good luck for the next step!