Do biner brake rapels work on anything other than ovals?
Depends on your definition of “work”, I think. You need to have the sides lined up with the gates opposed, and if you don’t have ovals, they won’t line up. Also, those funky light biners with non-rounded profiles would be harder to run the ropes over, and I imagine the more metal you have, the better the brake will be at dissipating heat. I always carry (at least) four ovals. A carabiner brake is my rap device of choice, so if I plan to rap I always have them available; if not, I use my chalk bag biner, my sticht plate biner, the cleaning tool biner, and an free biner.
