Dyna wobble at high speeds. Again.
Road Master
Joined: Jan 2024
Posts: 808
Likes: 194
From: Trinidad
If the problem started after replacing the rear wheel bearing, that is where I would start checking. Especially since there was some fitment issue with the spacer.
The new bearings could be faulty, or the wrong size. Or, excuse me for suggesting this, they could be incorrectly installed. The bearing seat in the wheel hub could also be damaged.
And as a general comment, my 2002 FXD runs well above 100 mph without even a hint of wobble. I can let go of the handlebars at any speed.
This is with all OEM components, no fancy stabilizer links or such. I personally think this whole death wobble thing is just poor maintenance
The new bearings could be faulty, or the wrong size. Or, excuse me for suggesting this, they could be incorrectly installed. The bearing seat in the wheel hub could also be damaged.
And as a general comment, my 2002 FXD runs well above 100 mph without even a hint of wobble. I can let go of the handlebars at any speed.
This is with all OEM components, no fancy stabilizer links or such. I personally think this whole death wobble thing is just poor maintenance
Road Master
Joined: Jan 2024
Posts: 808
Likes: 194
From: Trinidad
Hi all! A month ago i found a problem with my Dyna Fat Bob (2008 FXDF), at 70 mph rear wheel starts wobbling.
In winter, i disassembled bike for repainting and to replace some parts. What i replaced:
- Engine mouns.
- Fork oil.
- Tires (with balancing).
- Wheel bearings.
- Install chain conversion kit.
- And a lot more, but I don't think that's relevant to the problem.
After that there were problems with wobbling, it's hard to say what caused the problem, since a lot has been done and replaced. What have i done to try to fix the problem:
- Replaced swingarm bearing and bushing. Now the wobbling starts at 80 mph.
- Replaced neck bearings.
- Replaced rear shocks.
- Checked brake disks (rear <-> front) aligment, ~1 degree diffrence all OK. (Hmm... Maybe check the stabilizer link???)
- The rear axle is adjusted correctly, checked many times.
When i changed the bearings in the rear wheel, i noticed that the spacer is longer than the wheel hub (see spoiler), this does not allow the bearing to be completely inserted. Is this normal? Maybe the spacer was replaced by the previous owner from another bike?
Maybe someone has an idea what can be done or checked. Thanks for the help.
In winter, i disassembled bike for repainting and to replace some parts. What i replaced:
- Engine mouns.
- Fork oil.
- Tires (with balancing).
- Wheel bearings.
- Install chain conversion kit.
- And a lot more, but I don't think that's relevant to the problem.
After that there were problems with wobbling, it's hard to say what caused the problem, since a lot has been done and replaced. What have i done to try to fix the problem:
- Replaced swingarm bearing and bushing. Now the wobbling starts at 80 mph.
- Replaced neck bearings.
- Replaced rear shocks.
- Checked brake disks (rear <-> front) aligment, ~1 degree diffrence all OK. (Hmm... Maybe check the stabilizer link???)
- The rear axle is adjusted correctly, checked many times.
When i changed the bearings in the rear wheel, i noticed that the spacer is longer than the wheel hub (see spoiler), this does not allow the bearing to be completely inserted. Is this normal? Maybe the spacer was replaced by the previous owner from another bike?
Spoiler
Maybe someone has an idea what can be done or checked. Thanks for the help.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,923
Likes: 8,027
From: poway
Saw the pic.. Looks like a 2007 or earlier wheel and the spacer for the wider bearings.. Time to call in @multihdrdr 
Banned
Joined: Jun 2022
Posts: 673
Likes: 409
It's a 95" with medium hot cams so maybe more rev happy than a stock engine.
But thats off topic, my point was that a well maintained Dyna with everything in order does not wobble, even in stock configuration.
I recently changed from spoked to mag wheels, and that definitely made it smoother at high speeds. I think the spoked wheels are perfectly round when they leave the factory but over years of use I suspect they will go slightly out of alignment, enough to add some vibration at high speed.
Banned
Joined: Jun 2022
Posts: 673
Likes: 409
Saw the pic.. Looks like a 2007 or earlier wheel and the spacer for the wider bearings.. Time to call in @multihdrdr
Thread Starter
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Novice
Joined: Mar 2024
Posts: 23
Likes: 4
From: VRN
From the pic you attached, the sleeve looks proud in the rotor side of the rear wheel. That, in my experience is wrong. Like mentioned, you usually install the brake rotor side bearing first, making the sleeve slightly proud on the pulley side of the rear wheel. I would need to read the service manual for your specific year/model bike to confirm this...
Spoiler
Last edited by SHVED; Jun 2, 2024 at 04:05 AM.
Thread Starter
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Novice
Joined: Mar 2024
Posts: 23
Likes: 4
From: VRN
Stock from another Fat Bob.
I will try to tighten the bearings more tightly, but the wobbling is almost not felt from the front, i think that everything is fine with them.
Thread Starter
|
Novice
Joined: Mar 2024
Posts: 23
Likes: 4
From: VRN
Saw the pic.. Looks like a 2007 or earlier wheel and the spacer for the wider bearings.. Time to call in @multihdrdr
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Road Master
Joined: Jan 2024
Posts: 808
Likes: 194
From: Trinidad
Hi all! A month ago i found a problem with my Dyna Fat Bob (2008 FXDF), at 70 mph rear wheel starts wobbling.
In winter, i disassembled bike for repainting and to replace some parts. What i replaced:
- Engine mouns.
- Fork oil.
- Tires (with balancing).
- Wheel bearings.
- Install chain conversion kit.
- And a lot more, but I don't think that's relevant to the problem.
After that there were problems with wobbling, it's hard to say what caused the problem, since a lot has been done and replaced. What have i done to try to fix the problem:
- Replaced swingarm bearing and bushing. Now the wobbling starts at 80 mph.
- Replaced neck bearings.
- Replaced rear shocks.
- Checked brake disks (rear <-> front) aligment, ~1 degree diffrence all OK. (Hmm... Maybe check the stabilizer link???)
- The rear axle is adjusted correctly, checked many times.
When i changed the bearings in the rear wheel, i noticed that the spacer is longer than the wheel hub (see spoiler), this does not allow the bearing to be completely inserted. Is this normal? Maybe the spacer was replaced by the previous owner from another bike?
Maybe someone has an idea what can be done or checked. Thanks for the help.
In winter, i disassembled bike for repainting and to replace some parts. What i replaced:
- Engine mouns.
- Fork oil.
- Tires (with balancing).
- Wheel bearings.
- Install chain conversion kit.
- And a lot more, but I don't think that's relevant to the problem.
After that there were problems with wobbling, it's hard to say what caused the problem, since a lot has been done and replaced. What have i done to try to fix the problem:
- Replaced swingarm bearing and bushing. Now the wobbling starts at 80 mph.
- Replaced neck bearings.
- Replaced rear shocks.
- Checked brake disks (rear <-> front) aligment, ~1 degree diffrence all OK. (Hmm... Maybe check the stabilizer link???)
- The rear axle is adjusted correctly, checked many times.
When i changed the bearings in the rear wheel, i noticed that the spacer is longer than the wheel hub (see spoiler), this does not allow the bearing to be completely inserted. Is this normal? Maybe the spacer was replaced by the previous owner from another bike?
Spoiler
Maybe someone has an idea what can be done or checked. Thanks for the help.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,923
Likes: 8,027
From: poway
The bearings are installed correctly following the manual. In the picture on the reverse side there is no bearing at all, i put a metal circle almost the size of a bearing to make sure that the spacer is larger than required. I think that the long spacer is the problem, the bearings are pressed against the inner ring, while nothing prevents the hub from moving along the outer ring (bearings are installed tightly, but not enough to fix the wheel otherwise we would not have been able to pull them out at all), especially at high speeds and turns.
I think that the spacer should be shortened, but I'm not sure that it will be correct.
Spoiler
I think that the spacer should be shortened, but I'm not sure that it will be correct.
That is fine.. It's the way they are set up from the factory. They rely on press fit to control axial play.. If they bearing are loose you got problems..