We run the rubber bumpers here. When we run the heads full speed it does like slam more than I like, but its not the worst. Haven't noticed any bouncing, but I'll be looking for it now. Maybe try one or two before you go replacing all of them. Some like em, others don't. I like em myself. The less parts I have to replace, the better. these dont look like they will ever wear out to me. I picked them up from Aero / Crazy Ricks field of parts.