Motorcycle Safety & Driveability: Motorcycle front shimmy, wobble, front

Question
Have you ever heard of a Harley Davidson 2009 StreetGlide front wheel going
into an uncontrollable shimmy while driving it? Wondering if this has happened
to anyone else.

Answer
I don't think it's "normal," but I'm sure it happens from time to time.

My recommendation is to contact a suspension tuner/expert. There about 1,000,000 things that could cause this. For example, last year, our state patrol motor unit found that the police equipment and fairing on the front of their bikes changed the aerodynamics in such a way that it caused the front end to lift and shimmy at high speed.

It could be a tweaked fork leg, mismatched suspension settings, bad tire, bent wheel, torqued triple, shot bearing, any number of things.

On a new bike like that, the first thing I'd do is make sure the forks are set up exactly the same: preload, damping, and position in the triple clamp. Even 1mm difference in where the fork leg is clamped in the triple could cause this. If they're both clamped too high up on the fork legs, it could also cause this. Make sure the angle of the forks is exactly the same. You can use a piece of glass as a straightedge, lay it on the fork legs, and see whether or not the forks touch the glass in all four places at once.

Also, make sure your steering head bearing isn't loose. It may not have seated properly at the factory or it may need to be adjusted right away after the initial break in period of the bike.

Unfortunately I'm not a suspension tuner, I only know enough about that black art to be dangerous!

Best of luck.