Crack climbing

Crack climbing is a type of rock climbing in which the climber follows a crack in the rock and uses specialized climbing techniques. The sizes of cracks vary from those that are just barely wide enough for the fingers to fit inside, to those that are so wide that the entire body can fit inside with all limbs outstretched. Many traditional climbing routes follow crack systems, as they provide natural opportunities for placing protective equipment.

In the context of climbing, cracks are classified by their width in relation to the climber's body: finger, off-finger, hand, off-width, and chimneys.

The walls of crack systems rarely run parallel to each other throughout the entire length of the crack; they frequently constrict inwards and open outwards in various places. Some of the most challenging climbs follow cracks which run through many different widths. Even when a crack is uniform in width, it may require a different approach for each individual climber—a hand crack for a smaller climber may be an off-finger crack for a larger climber.

Throughout the history of rock climbing, whenever traditional climbers seek to develop routes in a new area, they almost invariably follow crack systems which offer natural locations for placing protective equipment. The use of the term "line" as a synonym for "route" derives from this practice, as cracks often form visually distinct lines that can be followed from base to top.

Prior to the introduction of spring-loaded camming devices, there was no suitable method for placing protective gear in off-width cracks, which made such routes extremely dangerous even when they were not technically demanding. It was not until the 1980s that extra-wide camming devices proliferated, enabling climbers to safely ascend off-widths.

By the 1990s, crack climbing had diminished in popularity for a variety of reasons. The advent of sport climbing allowed climbers to focus on difficulty and aesthetic appeal when developing new routes; it was no longer necessary to learn specialized crack techniques in order to lead climb safely. Furthermore, cracks are difficult to simulate in climbing gyms, so those who train indoors are limited to face routes when they climb outside.

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