The GO Outdoors Rope Buying Guide
Climbing rope is dynamic which means it has a lot of stretch in it to distribute sudden forces caused by a fall.
Ropes are used to help prevent the climber from falling to the floor and also to lower climbers safely as in abseiling
Single Ropes are the norm in indoor, sport and single-pitch trad climbs. The only exceptions to this are trad routes with wandering lines, where half ropes are necessary to prevent excessive amounts of rope-drag.
Half ropes, with regard to strength and weight, lie between single and twin ropes.
They only offer standard safety when they are used as a pair. But here you have the choice between twin rope technique, where both ropes run parallel through the protection and half rope technique, where the «left» and «right» ropes run separately through different protection points. This technique allows friction to be reduced in the case where protection points are widely spread and reduces impact force.
This is of benefit when climbing traditionally protected routes. A belay method which enables the independent control of each rope must be used. They come in diameters from 8-9 mm. In single strand form they are suitable to belay two seconds.
With two ropes of the same diameter, the higher the proportion of that diameter taken up by the sheath the more hardwearing the rope can be expected to be. There is a trade-off, however, as a thicker sheath also means reduced handling qualities (i.e. the rope will be stiffer, and may not run as smoothly through friction points)
The drop test measures how many standard falls a rope will withstand before snapping completely. The standard fall with a fall factor of 1.75 is an extremely hard one, which very rarely occurs in practical use. A weight of 80 kg (with single ropes) or 55 kg (with half ropes) falls on a single cord . Single and half ropes must withstand at least 5 standard falls.
The number of falls is a direct measurement of a rope’s safety reserve. No new rope can break from an impact load, assuming good conditions and good rope management. But the efficiency of a rope decreases: aging and wear reduce its strength. Moisture and particularly frost can reduce it by about one or two standard falls. In reality, 95% of ropes are retired because they become unusable due to the sheath becoming too ‘furry’ and causing too much friction, resulting in difficulty using belay devices, large amounts of rope drag, and higher impact forces.
The impact force measures the force imparted to the climber’s body during a standard fall. The measurement tells us about a rope’s ability to absorb energy in a fall, in order to reduce the impact on the climber’s body. Thus, lower impact forces are desirable. In standard tests the impact force for single and twin ropes may not exceed 12 KN and for half ropes 8 KN. The practical relevance of the impact force is not as great as it may seem because it is measured with the standard static fall test, i.e.: the fall rope is completely fixed. In practice, however, a fall is almost always caught dynamically. Measurements of typical sport climbing falls show that with dynamic belaying the difference in impact force between two different ropes is barely discernible.
Sheath slippage levels should be as low as possible, as if the sheath and core slip during climbing.
Knotability is a reference point for the stiffness of a rope; with a higher rating the rope will be stiffer to tie knots in and will in general not handle as well as a more supple rope. This is not related to safety, and is more of a concern to climbers operating at intermediate to advanced levels. The suppleness of a rope is also determined by care and the weather, so the knotability rating is not the only factor which will in practice determine a rope’s handling characteristics.
Static elongation indicates the elasticity of a rope with a static load. A piece of rope preloaded with 5 kg is loaded with 80 kg: elongation may not exceed 10% for single and twin ropes, and 12% for half ropes. Static elongation mainly assesses comfort when top roping or hauling on big walls. In these cases, it’s annoying when energy is wasted through rope stretch, or if a difficult sequence has been climbed with a top rope and while resting this distance is lost.
Dynamic elongation is directly related to impact force, and thus it is necessary to have a certain degree of dynamic stretch in order to achieve an amenable impact force. However, assuming the same impact force, it is preferable to have a lower dynamic stretch to avoid hitting a ledge or the ground on rope stretch.
Rope Diameter variations in each category signify the outer sheath thickness, not inner core. So an 11mm rope will be more resistant to abrasion than a 9.5mm but will both have the same core thickness
Rope can be “dry treated” this is a water repellent coating that helps protect against water, useful for sea cliff climbers.
Dry treating also makes the rope feel smoother, so providing more slick handling for longer, great for regular use.
Slings are used to wrap around a rock, tree or other fixed point either to secure a climber or create an anchor when setting up a top rope.
Slings can also be used to extend quickdraws to reduce rope drag.