In reply to BolderLicious: I thought it made everything slippery- which is the thick coating of chalk so beloved of bobble hatted but topless boulderers was sub- optimal compared to using just enough to dry your hands.
> Ron Fawcett says that chalk makes footholds slippery.
He's right but with one curious exception: when a hold - particularly limestone - becomes polished to a very high sheen a light dusting with chalk can actually improve the grip. In all other cases it seems to make things more slippery
In reply to BolderLicious: Yep. I was climbing a route in a quarry near the gower. The route consisted of friction moves on sloping holds and smears on a slab. It was hard from the floor up but when I got about 2/3rds of the way up I could see I was about to fall off because the next 2 foot holds were absolutely caked in chalk. I blew as much off as possible and managed to rub some off with my sleeve but I hadn't made much difference as I couldn't get the chalk out of the grain. It was no surprise when I stood on the hold that I came off. To me why would adding another element between rock shoe and rock do anything other than reduce friction (we are talking dry conditions here). Rock shoes are the equivalent to a racing tire on a F1 car and they try to keep the tires free from any particles as they know the car will spin out if the contact point to the track is tarnished.
> Yep totally agree, its looking at friction co-efficients, it is possible that the interaction between chalk and rubber could be a positive one as well (increase co-eff).
Well it's possible ( we can't be sure unless somebody does the research)
but I can't imagine what the mechanism might be.
Shoe rubber is after all designed to give good grip. If chalk is better than we've all been wasting a lot of money on rubber for a long time
Talc is entirely different to chalk. Put some talc on your hands and go climbing to see what I mean.
To the OP
Chalk for hands definitely improves friction in certain conditions. It seems to make your skin slightly less elastic and less greasy which helps your skin to mould to the irregulariies of the rock. The place for chalk is on your skin, not on the rock and certainly not on the soles of your shoes.