My girlfriend and I bought new 21" front wheels and tires and new 200 back wheels and tires at the Lone Star Rally. We bought the same wheels and tires except hers was chrome mind was black. We both ride 2012 Ultra Classic Limited's.

On our 1st ride over 73 mph her bike started a wobble, as she went faster it got worse. Mind did not, I check mind up to 105 mph with no problems. Her bike stayed a week at the HD shop without finding a problem. The rally installer could not come up with an answer. She went back to her stock wheels and tires and the problem went away. I'm still running mind wheels and love them.

Has anyone experence something like this?

 

Wheels and tires might be masking an alignment issue.
My ride was great until I put on a new rear, then had to adjust alignment and all smooted out. The procedure is in the manual - it's not hard.