Rope Types Explained

Just as climbers may choose one climbing shoe for bouldering and another for trad climbing, many climbers may (eventually) own multiple ropes for different styles of climbing. When choosing a rope, the first thing is to know the type of climbing rope you’re looking for. There are three main types to choose from (all used and certified differently):

To identify which type of rope you’re looking at, these rope symbols will appear on rope packaging and are also marked on the rope ends. You may also see these icons on belay devices, when they describe what rope diameters the belay device is designed to work with.

While most rock climbers (particularly in North America) stick primarily to single ropes, it’s helpful to know when / why / where all three ropes types are used. Some ropes are also certified for multiple types, so knowing where your rope can do double (or triple) duty is also helpful. Now let’s talk about the details of the three types, starting with the most common, single ropes.

Single Climbing Ropes

If you’ve top roped or lead climbed on a dynamic rope, chances are it was rated as a single rope. Single ropes have the widest range of lengths and diameters available and are used in every type of climbing from indoor to outdoor, sport to trad, and single pitch to multi-pitch.

In the US, nearly every time a climber mentions a rock climbing rope without specifying it’s type, a single rope is assumed. The word single refers to the plan that this one rope will be the sole rope used while protecting a climber during a fall. If they fall, the single rope is designed to stretch and absorb some of the forces away from the climber, and also away from the protection / anchors.

Because a single rope is one of the few non-redundant parts of the climbing system, a single rope is made and tested (and certified) to handle a lot of this abuse. In fact, the UIAA strength test for single ropes requires that the rope statically catch an 80kg (176.37lb) weight falling 4.8m at least 5 times in secession on 2.5m of rope without breaking.

Additionally, the UIAA requires that each rope tested does not allow the anchor to feel more than 12kN (2697.70 lbs) or just about the weight of two cows, while not breaking. So the rope will take and absorb about 4000 lbs of force and turn it into less than 2700 lbs– 5 times without breaking. 🤯

It bears repeating: These tests ensure there is no human climber that could break a rope due to their size and weight.

Nerd Alert: Every rope has different amount of elongation (0 – 40%) making it is impossible to give an exact force that all ropes can absorb. If you’re really curious, you can play around with rope stretch calculators using specific fall height, weight, and elongation characteristics to see the impact.

Although there are over 900 models of single rated ropes available today, climbers buying their first rope will often pick a rope with a diameter around 9.8mm to ensure the rope is easy to handle and is wider with more sheath fibers for durability. The most common lengths are ~40m for indoor climbing and ~60 meters for outdoor climbing, depending on the gym wall height and/or the wall height of your local crag. Below are a few popular options of rope that WeighMyRack users own. These are some of the bigger brand names, and these ropes are typically easier to find online and in store.

Single ropes can go down to the tiny diameter of 8.6mm and still be certified, such as the Tendon 8.6mm Master 2XDry, the thinnest and lightest single-only rated rope on the market. Smaller isn’t always better: its small size can make it difficult to pair with a belay device, since many belay devices aren’t rated to handle a rope smaller than 8.9mm. Small ropes also tend to be more difficult to control and also tangle more easily.

Half (Double) Climbing Ropes

The next most common designation of rope type is the half rope, which is a bit confusingly ALSO known as a double rope. Halfs (or doubles) are used in much the same way a single rope is and in fact their UIAA testing method is nearly the same, though they only need to catch a 55kg (121lb) weight. The biggest difference compared to a single rope is that they are used as a pair, although they are clipped separately like a single rope.

The obvious advantage of climbing with 2 ropes instead of one is that there is redundancy in case a rock fall or a sharp edge were to damage or cut your rope. They are also perfect for meandering routes, to reduce rope drag. Half ropes also have the benefit of allowing the climbing team to double the length of their rappels, since they now can join two ropes and descend a full rope length’s distance rather than halving the rope through an anchor for a standard rappel.

The reason they work well for wandering routes is that the climber can choose which rope to clip. For example, they can clip the green rope for all the left protection and the blue rope for all the far right protection. This will significantly reduce rope drag versus a single rope that must zig zag up the same wall with one rope.

When catching a fall, the two ropes in the system also greatly reduce the amount of force that any one piece of gear absorbs, so they are ideal for areas where marginal protection is common.

There are some disadvantages with a double rope system. Managing 2 ropes is considerably more complicated than managing one. Doubling the amount of time flaking and stacking ropes is one thing, but as a belayer you must also have a good amount of practice managing slack in a system with two ropes that are often feeding at different speeds. The leader also needs to remember which rope to clip to reduce rope drag.

Half ropes are also not always sold in pairs as some might expect and since there are two they do cost more than a single rope. Regardless, half ropes should be bought together in a matched set to ensure they are the same length, diameter, and have the same elongation so they will stretch and handle the same. Half ropes are also thinner than singles so special care should also be taken to ensure your belay device is made to work with ropes that average around the 8.2mm mark.

In the US, half ropes would possibly be a climbers 3rd and 4th ropes, if they ever own them. Half ropes are most often used in the alpine, where meandering routes are common. They are also often used while ice climbing – so if your crampon or ice tool were to cut the rope there is still redundancy.

Some examples of half ropes that WeighMyRack users own and want are:

Most often half ropes are also certified as twin ropes, which we describe next.

Twin Climbing Ropes

Finally, the last and least commonly made rope type is the twin rope. Similar to half ropes, the twin rope is made to be used in pairs, but BOTH ropes should be clipped into every piece of protection. Twin ropes give added protection and redundancy, but do not mitigate rope drag like half ropes. Because of this fact, they function best in straighter terrain such as ice climbing, though it is not unheard of for Europeans to use this method in mixed or alpine routes as well.

Quick caveat: Most twin ropes are also certified as half ropes, so they can still be used to mitigate rope drag in wandering terrain.

To remember the difference of twin vs half ropes, you can think about twins as “conjoined twins.” The icon is also a helpful reminder with their overlapping circles that these ropes go together.

Because twin ropes are a two rope system some big advantages are redundancy and the ability to rappel full rope lengths. The real standout of the twin rope is its small size and light weight. Twins average below the 8mm mark in diameter and are often small and lightweight enough to be split up and carried by partners. Because they are made to be used together and clipped in pairs to each piece, Twins are tested by the UIAA in pairs. To pass, they must be able to catch a whopping 12 falls of that 80kg block, making them the most robust setup by far, which explains why folks who climb in sharp crampons and swing pointy ice tools can prefer them.

It should be noted that belaying and rappelling with ropes that approach the 7mm mark is tricky and two thin ropes significantly harder to manage and control. These ropes almost always have a dry treatment that adds to the slippery feel as well. When you throw skinny ropes down for rappel as you would a single rope, it is not uncommon for them to become a knotted mess.

Also, there aren’t many belay devices out there that handle the thinnest of twin ropes and controlling the weight of a climber with two skinny strands is not as straight forward as one might wish. Another thing to note is that because they are clipped together, twins can create more rope drag than a single rope, and though they are individually very light and small, climbing with twins can feel heavier and bulkier than with a single.

That said, here are some popular twin ropes that WeighMyRack users own or want to own:

Summary

In the US, the vast majority of rock climbing will take place on a dynamic single rated rope.

While alpine climbing or ice climbing, many climbers will choose to use dual certified half/twin ropes to mitigate rope drag on meandering ropes (a half feature), to add redundancy, and to increase the length of rappels.

You can absolutely use half/twins while multi-pitch rock climbing, as they are especially helpful for long rappels. Just remember, to increase the rope usefulness, keep your dry treated half/twin ropes for ice climbing separate from any half/twin ropes you use for rock climbing – as ropes will lose their dry coating as they rub against rocks.