Topic: What are some causes of high speed wobbling?

[ChopSticks]

My daily (Nightster) has been wobbling at high speeds on the highway lately and just wanted to know what I can troubleshoot. It's not little wobbles either, like some serious butt puckering welp this is it wobbling.

[Steve_K]

Start by checking tire pressure and wheel bearings.  Be sure tires are in good condition.   Check head stock and swing arm bearings and bushings. Check that engine mounting bolts are tight.  Then get back to us. Steve

[seanbarney41]

USD fork conversion not living up to expectations?

[MikeSimon]

USD conversion? How is the trail?

[ChopSticks]

Start by checking tire pressure and wheel bearings.  Be sure tires are in good condition.   Check head stock and swing arm bearings and bushings. Check that engine mounting bolts are tight.  Then get back to us. Steve

Thanks saw this reply a little late and it was really nice outside, so I troubled shooted a bit since the bike is almost completely stock and no new mods have been added BUT a new windshield, so I figured to take it off also checked the tire pressure, which was low 30-35 out of recommended 42. Which I had only done one of them instead of both to try to eliminate/pinpoint the issue. But definitely don't want to bring it back to the previous condition/setup because the wobbling was a pretty scary time.

Road yesterday, and will continue to monitor it at high speeds. In case I wanted to do a whole run through can you clarify "Check head stock and swing arm bearings and bushings." anyway to check these without pull the whole thing apart?

USD fork conversion not living up to expectations?

USD conversion? How is the trail?

Not sure what this means, can you expand? The bike has the stock USD fork set up with stock trail to my knowledge.

[SOHC4 Cafe Racer Fan]

Tire pressure and balance could cause it.  The more usual culprits are wheel bearings, headstock bearings or swingarm bushings. I've also had tire pattern cause a wobble on grooved highway surfaces.

[Stev-o]

Start by checking tire pressure and wheel bearings.  Be sure tires are in good condition.   Check head stock and swing arm bearings and bushings. Check that engine mounting bolts are tight.  Then get back to us. Steve

 BUT a new windshield...

My brother installed a small fairing on his Yamaha 1100 and it caused high speed wobbles in the turns [and I would pass him!]

Told him to take off that POS...

[AndyH]

Front wheel/tyre (sorry...tire  ) balance?

[strynboen]

my cbx had some small problems ,,use a vindshield..
.not direkt wobbel..more a Loose of  feel of the stering..but only over 160 kmt-100 mph..vitaut the vind shield it vas stabile all the vay op..

[Don R]

 I'm thinking I read some of the V twin wobblies were caused by the soft motor mount system letting the engine weight flop around in the frame. I think a bunch of Police bikes had this trouble too. There was a recall or at least a revised motor mount fix. I'm thinking youtube had a video of that issue. Not sure if it's the same thing as yours.

 Edit, videos show spoke problems, bent rims, and dry/failing rear wheel bearings as possibilities.

[tbpmusic]

Put your bike on center stand.
Grab the rear wheel and pull/push side to side - hard!!
If it moves sideways at all, the swingarm bushings are bad.
If it moves a lot, you're going to die soon...........