I went to the club at 10:45 to help Redline haul out.
I also scheduled Maurice to come have a look at the vibration with the engine.
We went out for a test run.
He says it is "weird". Not the kind of answer I want to hear from an expert. Maybe the propeller is out of balance, maybe the propeller is not well seated in the shaft. Maybe the strut is having problems.
I am not eager about taking out the strut. Let it wear out a bit before we go there.
Investigate further after haul out.