I know the HD frame flexes like a torsion bar, but riding the twisties today I noticed it is really flexy. Maybe it's always been that way but I don't know. I bet there is enough flex for a degree or two of lean out. With it sitting level in the garage I can step on the floorboards and lean the bike out and it stays leaned out. To the right I think the lower fairing stops it because it touches. All the bolts are tight and I can't figure if it's normal or not. I recently took the car off because there were way too many threads showing on the toe adjustments per the tech manual so I starter from scratch. I set lean at 1 out loaded and 3/4 toe and have the car wheel within .25 deg of perpendicular. Pulls a little left as slow speed or coasting but drag could do that. I will say it drives better that it has since I bought it after the adjustment.
I can feel mine flexing on certain roads but it doesn't seem like it is moving very much. I would probably check all the bolts again, the front brace brackets under the sidecar in particular.
top frame mount will loosen and move up and down upper frame rails
I will look at that upper mount. I only checked the slider under the car and the ubolts. It was really weird , on hard right handers the bike was way out there to the left.
The front mount was a little loose and moving on the car side about 1/4". That little slip got me to 5deg lean out when to the outside extreme. Let's hope a little locktite keeps that from happening again. No wonder it was squirrelly and I thought something was wrong. I think she is all aligned back up! Getting that SC wheel perpendicular is the hardest adjustment in my opinion.
That's why I don't use clamped mounts. These are the front mounts on a Suzuki S-40.
