Hey Toby, if you get a pair of under armor you won't chaffe. I use them surfing. Most of the chaffing I get is from walking back up the beach with the board when surfing or walking back upwind with the kite on those light days.

Since wearing these, I never chaffe. I can surf or kite surf all day with no problems. I definately recommend them regardless of which harness you are using!

The nitrous harness itself doesn't really chaffe all that much because the leg loops are up higher and not around your theighs, and they are nice and soft and do not move around.

I got torn up more by the waist harness than the seat harness because it was always spinning around my waist and sliding up and down when jumping... I'd get those nasty red rashes around my waist, sometimes to the point of bleeding, and the stupid bar would dig into my sternum!