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How to Choose the Best Climbing Rope

The new Sterling Nano IX (green) and the old Sterling Nano (blue). In hand the smaller diameter of the Nano IX is hard to notice (9.0 mm vs 9.2 mm).
By Jack Cramer and McKenzie Long
Tuesday June 9, 2015

The foundation of the basic rock climbing belay system is the climbing rope, yet shopping for one can be a bewildering task. There are so many manufacturers with so many models; plus various lengths, and bi-patterns, with or without dry treatments. It can be hard to make sense of it all. To help you sort through this mess we took ten of the most popular climbing ropes to crags, peaks, and choss piles to see which were the best. We learned a lot about those specific ropes and have shared that knowledge in The Best Climbing Rope Review. Here we take a broader approach and try to use our experiences from those tests to determine the underlying qualities that make up a good climbing rope.

Single Ropes Examined

Single ropes are by far the most popular systems and, thus, the primary focus of this article. But they are not all created equal. When shopping for a single rope there are several factors to consider.

Diameter (and Weight)

Many shoppers focus on diameter when looking for a rope, selecting the skinniest size their fear tolerance and wallet can handle. Manufacturers have responded to this behavior and begun to market thinner and thinner single ropes. But this trend ignores the reason why most climbers prefer a skinny rope in the first place: lower weight. Sophisticated consumers may have noticed that while rope diameters have gotten significantly smaller over the last few years, weight has only marginally decreased. This is because companies are weaving the sheaths tighter and tighter to reduce the diameter, but are still using the same amount of material to preserve the strength and durability. So the weight stays the same. Production costs and prices have increased, but the performance may not have improved much for the average user.

It is easy to understand why this is happening; diameter is easier to see or feel in your hands than weight. It is also the primary metric used to advertise and discuss ropes. You hear it all the time at the crag, "Hey, how thick is this rope?" You cannot fault the manufacturers for recognizing this. But at the top of a long, pumpy pitch, extra ounces become the difference between sending and falling. Not the diameter. The same is true in the mountains where carrying a heavy rope can sap your energy long before you even get to the climbing.

Additionally, there is no standardized way of measuring diameter. It is not uncommon for ropes from different companies with identical advertised diameters to look and feel dramatically different. This could be due to measuring the width under tension or other nefarious practices, but the point is that diameter by itself is not a reliable way to differentiate ropes. It is far better to combine it with the weight to get a better understanding of a rope's construction and performance.

Moving past that rant, you still need to buy a rope, and ropes are still marketed primarily by diameter. Here is an overview of how ropes can be roughly classified using this as a metric. Take weight into consideration after you decide which size category is right for you.
  • Thick Workhorse Rope — (10.2 — 9.8 mm or >60 g/m)
These are the most durable options and will most likely outlast the skinnier competition.
Ideal Uses: gyms, big walls/aid climbing, extended top-roping, locations with rough rock
+ Durable, best value
- Heavy, bulky, sometimes too much friction
  • Medium All-Around Ropes — (9.7-9.4 mm or 55-60 g/m)
Medium diameter ropes provide the most versatility and are also the most popular. One of these is our recommendation for first time rope buyers.
Ideal Uses: Sport or trad climbing, multi-pitch, top roping, ice climbing, etc… anything!
+ Good balance between weight and durability
- A compromise for some specific uses
  • Skinny Sending Ropes — (<9.4 mm or <55 g/m)
Skinnier ropes come with a high price tag and lower longevity.
Ideal Uses Alpine climbing, hard redpoints, freeing big walls
+ Lowest weight and friction
- Decreased durability, care needed to catch falls


The specs on a selection of bargain ropes  circa 1999. Note  how heavy and thick they were  and how cheap!
The specs on a selection of bargain ropes, circa 1999. Note how heavy and thick they were, and how cheap!

During the foundational years of climbing, a 50 meter rope was the standard. The weight of a rack then composed of oval carabiners and chrome-moly pitons limited the amount of protection that could be carried and, accordingly, the sensible length of each pitch. Modern lightweight gear has reduced this burden and allowed climbers to safely protect longer and longer pitches. For awhile, 60 meter ropes became the norm. Today, these are still the most common, and are able to get you up and down lots of routes. But their popularity is beginning to wane as more route developers place anchors that require a 70 meter rope to lower to the ground. Furthermore, among strong sport climbers longer routes are trendy and 80, 90, or even 100 meter ropes are gaining acceptance.

Our best advice to first-time shoppers is to ask your climbing partners what length is ideal for your area. At many locations, 70 meters will be overkill. Also consider the type of climbing and intended grades. Generally, difficult single pitch cragging or bold multi-pitch linking will require a longer rope, while the easier grades or more patient parties can get by with a shorter cord. For many locations 60 meters will suffice, but if you can handle the extra cost, weight, and bulk, 70 meters might allow more possibilities.

Middle Marks and Bi-Patterns

Six different types of middle marks. From top to bottom: A factory bipattern  the rumble strip thread on the Mammut Sensor  faded factory middle mark  faded at-home marking pen  floss sewn through the sheath  and temporary chalk smears.
Six different types of middle marks. From top to bottom: A factory bipattern, the rumble strip thread on the Mammut Sensor, faded factory middle mark, faded at-home marking pen, floss sewn through the sheath, and temporary chalk smears.

Another important factor affecting the price and functionality of climbing ropes is the marking of the middle. Easy identification of the middle allows you to quickly thread the rope before a single rope rappel, or helps you measure whether you can safely lower a climber to the ground after a single pitch lead. There are a variety of options. The most dramatic method is called bi-pattern, in which the rope is divided into contrasting patterns that are easy to visually differentiate. One common pairing is an elegant argyle with generic static fuzz. To make a bi-pattern rope, companies have to weave the separate patterns into one rope of the desired length, which takes time and increases the price.

A more affordable way for manufacturer's to mark ropes is to do it after they have woven super long lengths of one continuous pattern. Individual ropes can then be cut off of this uniform spool to the desired length. The middle of each rope is then colored in some way. We like the idea, but in practice, this mark is too often a 6" long dull black smear that wears off quickly and is nearly impossible to see on a darkly colored rope. A few companies have recognized this nuisance and are now using longer-lasting methods with brighter colors. We applaud this.

If you ever need to mark a rope yourself, be it on a cheap unmarked rope, a worn away factory smear, or an asymmetrically shortened bi-pattern, there are several effective methods. A marking pen is one of the easiest, but use one designed specifically for ropes, not any old Sharpie, which can damage nylon. This coloring will eventually wear away and need to be reapplied just like a factory middle mark. Some climbers foolishly use tape. This can jam in a belay device, or worse, slide away from the middle and dangerously change the mark. A more effective mechanical technique is to sew thread through the outer fibers of the sheath. Floss works well, although, this method can unsettle partners who haven't seen it done before.

But what do you do on the top of a pinnacle after ignoring all these options when you realize you're facing ten rappels with an unmarked rope? The answer is simple, yet unknown to too many climbers; chalk. You will still have to measure the middle when threading the rope through the anchors the first time. Then mark the middle using a small pebble of the white stuff from your chalk bag. Use your fingers to really grind it in. Separate zebra stripes help make it obvious. Be sure to reapply at every other anchor or so because it will wear off. And, as you should anytime you're rappelling, always visually watch the ends of your rope.

Dry Treatments

Ice climbing is one situation where dry treatments become important. Not only can the ice warm up and melt but the rope is often flaked directly onto the snow where it doesn't take long for moisture to soak in.
Ice climbing is one situation where dry treatments become important. Not only can the ice warm up and melt but the rope is often flaked directly onto the snow where it doesn't take long for moisture to soak in.

According to rope companies, when wet, a rope can lose a significant amount of dynamic strength, up to 30%. A thoroughly soaked rope also adds substantial weight. Therefore, it is definitely best to try to keep your rope away from water. Moisture, however, cannot always be avoided. Sudden rain showers, wet slimy seeps, or ice climbing in general, can all get your rope wet. To prevent a rope from absorbing moisture, manufacturers can apply a water repellent coating at the factory. Each company seems to have their own name for their proprietary treatment, but in our experience they all perform about the same. A combined core and sheath coating is superior to a cheaper treatment of only a core or sheath.

Dry treating has further advantages beyond simply keeping a rope dry. These coatings also reduce friction—both on the surface and inside the fibers—which decreases rope drag and extends lifespan. Generally a non-dry rope will be a little cheaper than the dry version. However, aside from exclusive use in the gym or desert, we feel the higher cost of a dry rope is justified by the performance benefits.

UIAA Specs

Any rope sold for climbing should be approved by the International Climbing and Mountaineering Federation (UIAA) and include on the packaging the scores measured for each of the few required tests. While it may be tempting to geek out on these numbers, it is most important to just know that the rope is UIAA certified. We will try to explain the tests as best we can, but for a complete explanation see the actual UIAA Safety Standards.

UIAA Fall Rating

This test uses an 80 kg (176 lbs) weight attached to a 2.5 meter length of rope. The weight is repeatedly dropped from a height of 2.3 meter to create harsh, greater than factor 1.7, falls. The final fall rating is simply the total number of these falls a rope was able to catch before failing. These falls are extremely severe and unlikely to occur often, if at all, in a real world setting. In fact, there has yet to be a confirmed case of a UIAA approved climbing rope failing from the force of a fall alone. Therefore, as long as a rope passes the UIAA minimum 5 fall requirement, we believe this number is of little importance.

Some have argued that this number can indicate the overall lifespan of a rope; a higher number equating to more durability. While it would be convenient if this were true, in our experience ropes are more often retired from damage to the sheath (partial or full core shots), or declining handling, than from an actual reduction in strength. A good example of this contradiction is illustrated by the Sterling Nano IX and Marathon Pro. Both withstood 6 UIAA falls, but the Marathon Pro's higher weight, diameter, and massive sheath makes it undeniably more durable. To summarize, we think the fall rating number is a good a measurement of core strength, but does not tell you much about the most likely cause of retirement, the sheath.

Impact Force

Exploring the elasticity of the Mammut Sensor. It withstood ten falls in the UIAA's drop test and placed in the middle of the pack for impact force and dynamic elongation.
Exploring the elasticity of the Mammut Sensor. It withstood ten falls in the UIAA's drop test and placed in the middle of the pack for impact force and dynamic elongation.

Impact force is the amount of force exerted on the weight during the rating falls, in kilonewtons (kN). The lower the number, the lower the impact will be on you during your own falls. Additionally, a smaller impact force will also reduce the load on the top piece of gear. For clipping beefy bolts this is of little consequence, but it could be an important consideration with questionable gear or when ice climbing. In practice, though, the weight and actions of your belayer can have an even greater effect than the rope on whether a catch is 'hard' or 'soft'.


The elongation is measured under two different circumstances. Static is the amount a hanging rope stretches when the 80 kg weight is added. Dynamic elongation is the length of stretch when the same 80 kg weight undergoes the first UIAA test fall. For the label, both are converted to a percentage, so a 60 meter rope with 7.5% static elongation will stretch 4.5 meters (~15 ft) under an 80 kg load. Dynamic elongation appears to be closely correlated with impact force, and the same considerations for marginal protection should apply.

Sheath Slippage

The UIAA pulls 2 meter segments of rope through an apparatus that exerts pressure from multiple angles to measure the amount that the core and sheath stretch compared to each other. Sheath slippage can be an annoying real world problem as the two parts separate during rappels, creating floppy, sheath-only, ends that necessitate chopping. But we're not sure if this test is an effective way to measure it. All of the ropes tested received a 0 mm score except the Sterling Nano IX, which got 5 mm. However, we experienced no slippage on the Nano IX, only with the New England Alex Honnold Signature Bi-Pattern Glider. This mystery remains unsolved.

Other Considerations

Sheath Proportion

The 42% sheath proportion of the Sterling Marathon Pro was the highest tested. This combined with its heavy weight (63 g/m) helped it receive the best score for durability.
The 42% sheath proportion of the Sterling Marathon Pro was the highest tested. This combined with its heavy weight (63 g/m) helped it receive the best score for durability.

Although it is not a UIAA requirement, many manufacturers are now including a sheath proportion number on their packaging. This is the portion of sheath relative to core by weight. We were hopeful that this could start to provide some insight into durability, but that insight turns out to be limited.

First of all, it is too easy to focus on only the number. Take the Petzl Volta and the Sterling Marathon Pro. Both have an identical 42% sheath proportion. But the Marathon Pro weighs 8 g/m more, and this 14% heavier sheath is predictably more durable. So sheath proportion is really only useful when comparing ropes of similar weight. Secondly, as one rope designer explained to us, the durability of a sheath is affected by more than just the total amount. Yarn type, denier, and thickness combined with the carrier count, twist levels, and dye process can all have a significant impact on sheath longevity. Instead of getting bogged down with these details, we hope you will trust our testers and the overall durability numbers they've settled on after climbing with each rope.


During the testing phase of this review we spoke with many climbers about the qualities they look for in a climbing rope. By an overwhelming margin, the most common response was low price. This is somewhat surprising when you consider that we all trust our lives to our climbing ropes, literally. But the UIAA has done such a good job with their certification process that there is almost no concern of purchasing an unsafe rope. Furthermore, many performance characteristics of ropes—handling, catch, durability—are difficult to measure or articulate, so a lot of shoppers have shifted their focus to the most tangible metric: cost. If you're a part of this frugal group, we have a simple suggestion for you.

Shop the sales, but be wary. There are many websites that offer deals on ropes at sharp discounts off MSRP. Often this is due to an ordinary overstocking mistake, but sometimes it's because of an actual quality issue that results in a rope no one wants to buy. It could be unpleasantly stiff handling, a sheath prone to slipping, or any number of legitimate defects. Whatever it is, you can elude these lemons by checking reviews before any sale purchase. It doesn't have to take long. From our experience, the majority of climbing ropes perform at a satisfactory level. The few bad apples mixed in should be easy to spot with just a glance at what other people think.

Some ropes that initially handled well became stiff after heavy use. Here is a comparison between three diffrent workhorse ropes at the end of testing  from top to bottom: New England Alex Honnold Glider  Mammut Sensor  Sterling Marathon Pro. The Marathon Pro felt the nicest to handle when actually climbing.
Some ropes that initially handled well became stiff after heavy use. Here is a comparison between three diffrent workhorse ropes at the end of testing, from top to bottom: New England Alex Honnold Glider, Mammut Sensor, Sterling Marathon Pro. The Marathon Pro felt the nicest to handle when actually climbing.

The 'Value' section we include for each rope reviewed is based on the manufacturer's suggested retail price. Consider the opinions we've written, but if a lower scoring rope can be found at a substantial savings, it might be your best option. OurdoorGearLab generates revenue through clicks to the retailer links we have included on our pages. So if you appreciate these reviews, do us a favor and follow the links to any great deals you might see shown here.

Jack Cramer
About the Author
Between his passion for all things climbing and his scientific work aboard commercial fishing boats, Jack estimates he gets to spend more than three quarters of each year outside. He hopes to save the world by helping to preserve the Pacific Halibut fishery and by eliminating the waste of misguided gear purchases.

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