The roller diameter on the piano legs are the issue.
They aren't 16" wheels, so the psi is enormous and the wheels are not "perfectly constructed" for the job they do.
Many are cast, and they are not to 'Boeing specs'. I don't want to start a 2000 post, 66 page argument, but boys and girls, oak flooring is not really that hard. I cam see all the old timers jumping through their
butts, but care will solve the moving issue. We always use a sliding device under heavy loads and NEVER roll appliances, furniture or slide anything unless it is protected.
81 degrees here today, black flies helped me donate about a pint, and the mosquitoes sucked another pint.....gettin' dizzy!
3 clicks, 4.5 air 25 lb a a day now. Hard to dampen down the hand feds......