For the uninitiated the range of ropes available can be a bit of a mine field. With the various diameters, uses, strengths and lengths - it can be very confusing. This straight forward guide will attempt to make choosing a climbing rope a little bit easier.
Single climbing ropes
Single climbing ropes are the most versatile and easy to use. They are designed as the name suggests to be used as a single rope and these vary in diameter from 10 -12 mm. Some more specialist single ropes go down to 9.1mm, but we would only recommend these ropes for more advanced climbers.
As with all rock climbing ropes these are ‘dynamic’, meaning they have an inherent stretch to them. This is designed to absorb some of the shock that’s transferred through the rope in the event of a fall. This helps to keep all your gear in place on the crag and more importantly reduces any sudden jarring on you at the end of the rope. This dynamic quality is very important for your safety when climbing, and you should never climb on a non-dynamic, or a ‘Static’ rope as they are called. Static ropes are used mainly for caving, canyoning and abseiling, where any stretch in the rope would be a serious disadvantage.
One disadvantage of a single rope is that it must be doubled over for a (retrievable) abseil; halving the overall length of the rope. This is usually not an issue with single pitch cragging, but can be a severely limiting on multi pitch mountain routes, which may require an abseil descent or an emergency abseil retreat.
If you are regularly climbing on multi-pitch, mountain routes with leader placed protection then a pair of half ropes offer lots of advantages over a single rope. The main bonus is that you can better protect meandering and non-direct routes, whilst minimising the rope drag that would be generated if using a single rope.
Another advantage is that you can use a pair of half ropes for full length abseils, rather than just the half length with a single rope. This is a real advantage in mountaineering and alpine climbing.
Half ropes are usually around 8 - 9.5mm in diameter. They are thinner, so obviously less strong individually than a single rope, yet combined as a pair they offer a much better margin of safety. A half rope should never be used as a single rope for climbing. They can be used singly for glacier travel and on less technical terrain though.
A pair of half ropes does complicate belaying and rope management, as there are two individual strands to control rather than just one. Half ropes also require greater thought when clipping in to placed protection. However, constructing anchors with two ropes is generally quicker, easier and safer than with a single rope.
Are a little bit more specialist and are mainly used by ice and alpine climbers. They tend to have a smaller diameter of around 7-8.5mm and like half ropes can’t be used singularly. The main difference in use from half ropes is that rather than clipping different protection points with each rope, Twin ropes are clipped into the same gear together – two ropes acting as one single rope as it were.
The main safety point of Twin ropes is that if one line is damaged or cut (a real danger when using sharp metal tools like ice axes and crampons, or if there’s falling chunks of ice) you will still have protection from the other rope.
Ropes come in a variety of lengths and the length you buy will be determined by what and where you are most likely to climb. The most popular length is 50 metres. This gives you plenty of scope to climb everything from single pitch crags to big mountain routes, particularly if you are looking at climbing mainly in the UK. The big disadvantage of using a 50m rope is that you can only abseil to a maximum of 25m (half its length).
60m and 70m ropes are very useful if you are looking to climb in the bigger mountain ranges, such as the Alps or Dolomites, where climbing pitches and abseils are quite regularly over 50metres.
Shorter rope lengths are also becoming popular due to their relative low cost and low weight. 30m and 40m ropes are available from many manufacturers. These are fine if you are only going to be climbing very short single pitch routes, but they do have limitations and lack the versatility of longer ropes. A 50 metre single rope is what we would suggest as a first rope or as an all-round general purpose climbing rope.
The thicker your rope the more durable and strong it will be. However, it will also be heavy and more difficult to handle the thicker it is. For example many modern belay plates will struggle to smoothly feed single rope over 11mm. To choose the right rope diameter for you consider how you are going to be using it. If you are going to be using it very regularly or with groups consider a thicker, more durable rope. If you are planning to use it less frequently, are climbing the harder grades or its going to be used predominantly for longer, multiple pitch routes, then look at thinner and lighter ropes.
As an example, a good all round single rope should be about 10mm - 10.5mm. This would be a good compromise between weight, strength and durability.
Dry or Not Dry treated?
Dry treatment is a chemical treatment which essentially waterproofs the rope. A wet rope will tend to stretch more, which could potentially damage the rope internally if shock loaded or in a short fall could mean you actually hit the ground. It will be heavier to carry and, if you are using the rope in winter conditions, it could also freeze solid if full of water. So a dry treated rope is a very good idea for use in mountain conditions.
However, dry treatment adds a significant cost to a rope (about 15% more than a non dry treated rope.) Also some dry treatments are better than others. If a dry treatment only covers the sheath, the outer part of the rope, it is of limited value. You should look for a dry treatment that coats each fibre both on the outer sheath and inner core such as Beal’s Golden Dry or Mammut’s Superdry treatments. Lesser sheath only treatments can also leach out of the rope when wet, acting almost as a lubricant through your belay plate, which you definitely don’t want. If you plan to use your rope mainly at an indoor climbing wall, or only dry weather outdoor climbing, then a standard non-dry treated rope will be fine.