Effectiveness of chalk as a friction modifier for finger contact with rocks

• Rock climbing is a popular recreational activity & competitive sport (e.g. Olympics).
• Outdoor climbing has wide range of locations, climates, rock types and conditions.
• Indoor climbing features resin holds bolted to the walls of climbing gyms.
• Friction at hand-hold interface is crucial to performance & safety.
• Loads through fingertips vary dependent on body weight, position and overhang.
• e.g. 70kg climber, assuming 25% body weight via one arm, is 13N load on middle finger pad.
• Climbers often use chalk or liquid chalk on their hands, but effectiveness not quantified.
• Chalk thought to dry hand from sweat and moisture and increases friction.
• Scientifically, this is likely to be a much more complex interaction.

Presented at East Midlands Geological Society 60th Anniversary Conference