By: Jens Larssen  | Date: 2005-11-15  | Category: Tips & Tricks    | (2) Comments  
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Different rope, different rope drag!

Rope drag is caused by friction on quick draws and the rock and can therefore be reduced by using longer quick draws. However, the performance climber should know that the rope itself has qualities that will affect. Hence, choosing the right rope for a hard press on a route with much rope-drag could mean the difference between success and failure when clipping the last bolt at 30 meters height;

  1. The surface of the rope; how well it slides across surfaces due to rope surface treatment and wear (i.e. rugged surface)
  2. The thickness of the rope; a thinner rope means less friction
  3. The weight of the rope

Over the years the ropes have become thinner, lighter and often water protected (which actually makes them more slippery). The weight difference (15 grams per meter) is less important for the drag but it is clearly that an 8.9 surface treated rope will cause less friction than an ordinary 10.5 mm. Friction is, however, mostly affected by the state of the rope, that is if the rope is old, worn and/or rugged or if it's brand new. Below we show an example on how the three factors mentioned above could affect the 'rope drag load' (i.e. how heavy it is to pull the rope) while pulling the rope at 30 meters.

Rope drag factors

New & treated
8.9 mm

Used & rugged
10.5 mm

Surface texture

1 kg

3 kg

Thickness

0.5 kg

1 kg

Weight

1.5 kg

2 kg

Load to pull rope

3 kg

6 kg



Rope manufactures often warn that a new, thin and treated rope could cause such a low friction that the braking effect of the belaying device is dangerously reduced. For example, everyone knows that it is very dangerous to use a new and thin rope in a GriGri but that regular usage with other devices will increase its friction and enable GriGri use. However, the trade-off is that at the same time the rope will become harder to pull through the quickdraws. BR>

Some additional pointers

  • Dynos in a steep overhangs will create a swing that is easier to control for the belayer with a high friction rope.
  • Single ropes are certified based on 80 kg tests. Half ropes, which are as thin as 8 mm, could pass as a single rope for children.
  • SUM is a new belay device covering ropes down to 9.1 mm.

    The thinnest rope on the market is Mammut 8.9 mm.
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