not sure if this is the right forum for this other than the fact that the masters of indoor crack climbing training seem to be brits, anyway...
a while ago i've been building a mini adjustable crack machine i can hang on a pullup bar, a sort of beefy rock ring...
the problem is that as the wood is megaslick and i am a weak crack climber i will slip out of the thing way too soon, much sooner than if it was built out of granite or sandstone.
so i am wondering which way of adjusting the intensity is better, between two options:
a) foot on (which i am currently doing)
b) adding grip in the form of glued on sandpaper (not too coarse as i don't want to tape).
any thoughts?