UKC

Ron Fawcett says that chalk makes footholds slippery.
I never noticed this before.Has anyone here fallen from a climb because
chalk made the foothold slippery?

In reply to BolderLicious: That might just explain why pretty much every bouldering wall in the country has a load of brushes on the end of a stick!

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.

In reply to Oceanrower:

They're mainly for cleaning hand holds, no?

In reply to BolderLicious:

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.

In reply to BolderLicious:

Chalk is the climber's equivalent of a flouro jobsworth jacket or a St Christopher medal stuck on the dashboard. You don't need it but it makes you feel better.

In reply to john arran:
I can't stand limestone-it all seems slippery compared to grit!

In reply to Rigid Raider:
Not what the recent science says.... http://www.ncbi.nlm.nih.gov/pubmed/23259237

I have no affiliation with this paper in any way, but do agree that it has a mental aspect, always allows me to calm down anyway.

In reply to BolderLicious:

I had to chalk up a polished starting foothold at Froggatt last week. It transformed the starting moves from almost impossible to very simple.

However, I can see how chalk on a non polished hold could decrease the friction available.

In reply to greg_may_:

Interesting paper. Thanks for the link.
However it is addressing a completely different question in that the general assumption is that
chalk helps by drying sweat & shoes don't sweat.

In reply to i.munro:

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).

Still, I tend not to waste time chalking both hands and feet while climbing

In reply to BolderLicious:

Chalk on foot holds? I thought all chalkies swore that they only used it parsimoniously to dry their sweaty hands?

In reply to greg_may_:



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

In reply to BolderLicious:

Chalk is multi functional. Yes, it absorbes moisture from surfaces, but is it also a lubricant, look at gymnasts.

In reply to kipper12:

Erm... chalk (well, talc actually but same thing) is also rather good for dry lubricating sticky new rubber bicycle tyres when fitting them to wheels. Go figure.

In reply to Rigid Raider:

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.