Power pads serve a function. They were first used on wood frames. They were used to take the stress off natural gut where it was making a sharp turn back into the next hole usually the first two set of holes on each side of the throat. They serve the same purpose today by cushioning and rounding the string path of the throat grommets.
Bradley Cranford you are correct they work very much like the woofer grommets in Babolat frames. Leather PPs will cushion the string (somewhat) but all PPs are not made of soft material. I have some PPs made of a hard plastic material they look like to half balls melted together. If anyone like to use PPs in their racket more power to them. I can tell when they (leather PPs) are in my racket but I have no preference.
Pete Sampras used power pads. Roger Federer uses it and made it popular. I looked at close up pictures of Del Potro and Warinka's racquets and they too use it. There has to be some commonality and value among these grand slam champions for using the pads. For me, I use to dampen the shocks, makes the strings last longer from the shearing at the crosses, enlarges the string bed, makes it look cool and unique, a topic of conversation when someone see's it and ask about it.
I’ve used PPs a lot, there may be a difference but I’m not good enough to see much difference. Several players I string for say it makes the use of vibration dampeners not needed. Back in the day of wooden racket they were used to round the string in the throat area to prevent breakage. I have some old plastic PPs that are rock hard.
No the leather I have is 7-8 oz leather or maybe about 1/8” thick. I see no need to double that. I have seen people roll up pieces of leather grip and use that though.
Yang Chen I’ve never heard of a recommended thickness. Some people like the feel of power pads truthfully I can’t tell much difference. If I use new PPs each time though I do think it may mute the string vibration sound just a little. Look at the woofer grommets on a Babolat racket. Some lift the string very little while some (especially in the throat) raise the string quite a bit. I use a thick leather but doubt it is necessary. I think if the pad is thick enough to round the string there is much less chance of the string breaking due to shearing.
김진영 they weigh about 0.15 g each. Because the weight is so close to the balance point of the racket there will be no change in balance. Three of them (0.45 g) mounted 30 cm from the butt will raise the Swing Weight by almost 0.2 Kgcm^2.
Eddie Kao I’ve never tried them but I would think the string would cut through rubber, and leather is more durable. You want something soft for cushioning but the main purpose if you round off the string bends at the grommets. Think about woofer grommets in a Babolat racket.
