I've made such a complete noob blunder with my disc wheel. I assumed that a set of normal but high quality bearings from the likes of SKF would be sufficient. Wrong. It's lovely and smooth, spins for ages... but it's completely silent. I should have got some cheap Chinese ceramic bearings #wheresmyrumblegone etc
I managed to ram 170psi in the back tub, about 10 shy of the limit. WOW, if you think stones fire out from under your tyres at normal pressures you should see it at silly-psi. I thought one piece of gravel was going to go clean through the door skin of a car this morning. Sorry to whoever it was, you've probably got a stone chip AND a nasty little dent