I’m having some trouble with slip (rotation) of the seat post on a Nimbus Muni. Those clamps are really tight now, but it still slips. I don’t think I can get them any tighter. I’ve taken the post out and tried to clean it (haven’t tried any solvents yet), but that didn’t help. There’s plenty of post in the top tube, probably 4 inches. Maybe I should try cleaning with something fairly mild like rubbing alcohol? Any other suggestions? My other unicycles don’t have this issue - only this one gives me trouble.
(that’s not rust around the top - it’s Sierra dust from the last ride.)