The Best Climbing Slings and Runners
Best Overall Climbing Sling
Mammut Contact Dyneema
The Mammut Contact Sling is the best overall climbing sling because it combines a winning combination of minimal bulk, super low weight, easy deployment, and comfortable handling. It is made from Dyneema, known for being the strongest fiber on earth, and pound for pound significantly stronger than steel. The tubular shape of its webbing means it can be a mere 8mm wide yet still provide the same 22kN strength rating of the thinnest flat webbing that checks in at 10mm. It's also the lightest sling in this review, weighing a meazily 19 grams. Due to its super slim dimensions, we found that this sling slides through carabiners easier than any other model which allowed us to triple it up into an alpine quickdraw with minimal hassle. This performance is aided in part by the low-profile stitching that used to connect the two ends to make the sling.
Of course, we discovered a few downsides to this low-profile sling as well. Due to its incredible thinness, we find that any knot tied into the sling has a propensity to weld itself together very tightly when weighted, which can make them quite hard to untie. Like all Dyneema slings, tying knots in the sling greatly reduces its strength. Dyneema is also inelastic so climbers need to be extra careful not to load the sling statically or the forces generated may damage the sling itself or whatever protection it is attached to. These concerns, however, are easily mitigated by attentive use, and we belive the benefits of Dyneema far outweigh its drawbacks. Since climbing is a game of getting you (and your stuff) up tall cliffs and mountains, having the lightest, smallest, and best performing gear seems to only make that task easier and more enjoyable. That's why we recommend the Mammut Contact Sling as our favorite choice.
Read review: Mammut Contact Sling
Best Bang for the Buck
Black Diamond Nylon Sewn Runner
In the battle between Nylon and Dyneema for the best material for climbing slings, Nylon has a few notable advantages. The most obvious is the fact that it is far more affordable than Dyneema, which is one of many reasons why the Black Diamond Nylon Sewn Runner is our Best Buy Award winner. This sling retails for less than half the price of some of the others in this review, so if you are forking over the cash to get a set of slings that will get you to the top of a route in the Red Rocks or Yosemite, then the cash saved could be significant (or at least enough for pizza and beer after your successful climb). Another advantage of Nylon is that it can dynamically stretches up to 30% when weighted in a fall. While the rope usually supplies its own dynamic properties regardless of which type of fibers make up your climbing slings, it never hurts to have extra shock absorption built into your climbing systems. This elasticity also makes Nylon a safer choice for anchor attachment, whether aid climbing or clipping up a via ferrata, or any situation where there is the potential to fall directly onto a piece without a rope to absorb some of the force.
Nylon, of course, has its downsides as well, or we would have never seen such a deluge of Dyneema slings flood onto the market. The main negatives are that in order to meet the minimum strength requirements for slings (22kN), a lot more Nylon is needed than the much stronger Dyneema. Nylon slings, therefore, are wider, bulkier, and heavier than Dyneema and some other fibers. These attributes compound when it comes to performance, because with more material, there is more friction when passing the sling through a carabiner, which makes Nylon slings slightly harder to triple up into alpine quickdraws or untie once a knot has been weighted. These drawbacks do matter, but only you can decide how much when weighing it against the price savings. After all, climbers have been climbing awesomely rad objectives for at least the last 50 years using Nylon slings (and a lot of other antiquated equipment). For the average climber, a few Nylon slings on the rack to compliment a larger amount of Dyneema ones can only add versatility, while a budget-conscious climber should be just fine going with only Nylon.
Read review: Black Diamond Nylon Sewn Runner
Best for Building Anchors
Metolius Open Loop Sling
Although double-length slings are most commonly used to extend pieces of protection while on lead to reduce rope drag, quadruple or even longer slings are sometimes used to equalize multiple protection pieces into a secure anchor. On a multi-pitch climb, it's common for each climber to carry 1-2 extra long slings for this purpose, and from our testing, we think the Metolius Open Loop Sling offers the best array of attributes to be an ideal anchor sling. While all Dyneema slings are joined with a small amount of Nylon on the edges to give it color and suppleness, the Open Loop Sling features a more equal balance of the two, which gives it some elastic stretch while still featuring the strength-to-weight ratio of Dyneema. It comes in a wide selection of different widths and lengths, making it easier to choose exactly what size sling you prefer for building your anchors. We tested the 11mm wide, 120cm long version, and thought it was one of the very best performers when it comes to tying and untying knots that have been weighted, which is a very critical consideration for an anchor building sling.
There are a few downsides to this sling, mainly that tying knots in a sling, which is common when building equalized anchors, reduces the strength of the sling. However, considering that the sling is rated to forces of 22kN (roughly equal to 4,945lbs) it is hard to conceive of a situation where a sling of even slightly reduced strength would be compromised. Other small downsides are the fact that it is a bit thicker than other slings we tested that are also 11mm wide, making it slightly bulkier, and it also has a slightly rougher edge to it than the tubular design of the BlueWater Titan Sling, another solid choice for anchor building. In the end, however, these concerns are far outweighed by the ease of untying knots and the myriad of choices, not to mention the very reasonable price, which makes this the ideal choice for your anchor building needs.
Read review: Metolius Open Loop Sling
Best for Using as Pro
Edelrid Aramid Cord Sling
Climbing slings are most often used to extend pieces of protection while leading, whether that be bolts, cams, or nuts. Another usage, however, is using slings as protection themselves. Slings can be tied around horns, girth hitched to trees, or threaded through holes. The best sling that we've tested for this purpose is the Edelrid Aramid Cord Sling, which earns a Top Pick award. Rather than being made of flat or tubular webbing, this sling is 6mm cord made with Aramid fibers, or more commonly known by the brand name Kevlar. These strong fibers have very high abrasion resistance which make them ideal for a sling to wrap over sharp edges. Their stiff, almost rigid, handling is in stark contrast to the floppy and supple feeling of most slings, so they're easier to thread or place one-handed while keeping a grip on the rock. Add to that Aramid's high heat resistance, something not found with Dyneema or nylon slings, and these can also serve as a great rappel backup or prussic cord should you need one in an emergency.
The downsides to these slings are that they are a bit bulkier and heavier than normal slings. The rigidity, combined with the rather large thermo-molded covering over the sewn ends, means you can't just crumple them into a ball to toss in the pack. It also means that they aren't as low profile on the harness when you have them tripled up into an alpine quickdraw. And like Dyneema slings, they have very little dynamic stretch. These are small prices to pay for the enhanced versatility. Although we were rebuffed in our attempts to fund a "testing" trip to the Italian Dolomites, they have been designed with this style of climbing in mind — traditionally protected limestone where the rock can be very sharp, and pocket or tufa threads are plentiful. For those of us in the States, slinging horns and chicken heads on the granite of the lower Merced in Yosemite or the domes of Cochise Stronghold could be ideal uses. They would also be a quick solution for v-thread anchors on multi-pitch ice climbs where their rigidity would make threading nice and fast.
Read Review: Edelrid Aramid Cord Sling
Best for Clipping Into a Belay
Beal Dynamic Sling
It is very common while multi-pitch climbing to clip into the belay using a sling, or to use a sling to clip oneself into a rappel anchor on the way down while you pull the ropes to rig the next rappel. We have done this literally thousands of times, usually with Dyneema slings, because that's normally what we have on hand. But for anyone who does this, we recommend watching this extremely informative, and sobering, video made by DMM. The takeaway is that with just a little bit of slack in the system, a small fall can generate catastrophic forces that are capable of snapping a sling, especially if there is a knot tied in it. To reduce this possibility, you can clip into the anchor using the rope or use the Beal Dynamic Sling. This sling is a sewn piece of 8.3mm climbing rope that offers of the shock-absorbing properties of a normal rope, making it ideal for tethering into the anchor. Beal has tested this sling for >20 factor one falls and >8 factor two falls, which is an enormous number more than an ordinary Dyneema sling could withstand (roughly 1 factor one or 0 factor two falls). So, whether you're rappelling, clipping in for just a moment while the belay device is switched so you can lead, or are leading in blocks, tethering in using the Beal Dynamic Sling should be safer than using a dyneema or nylon sling for the same purpose.
The downside to this sling is that it is far bulkier and heavier than a normal sling. We found it to be too bulky to easily triple up into an alpine quickdraw, so we had to carry it over the shoulder or tied in a knot on the harness. The spot where the two ends are sewn together is also quite large and doesn't easily slide through carabiners. Basically, this is not a sling we would buy simply to use as a normal sling, but we think that it is a versatile choice for use while clipping into anchors, which is why we awarded it our Top Pick Award.
Read Review: Beal Dynamic Sling
Why You Should Trust Us
This review is led by Andy Wellman, a climber of over 22 years. He has been a senior review editor at OutdoorGearLab for the last five years, and used to own and run Greener Grass Publishing, where he produced and wrote rock climbing and bouldering guidebooks to the Southeast, including Stone Fort Bouldering. He has a wealth of climbing knowledge gained from hard-earned experience in every discipline of climbing. He has also experienced first-hand the style, ethics, local community, and excellent stone at the vast majority of famous climbing areas in this country, as well as a few abroad, choosing to home base at different times in the climbing meccas of Boulder, Rifle, Chattanooga, Ouray, and now Terrebonne, OR — a stone's throw from Smith Rock. It's safe to say that he has used and abused a whole lot of climbing gear over that time! Adding to his knowledge is Chris McNamara, owner and founder of OutdoorGearLab and SuperTopo Guidebooks, who became famous for climbing countless frightening aid routes on El Cap before he was even old enough for college.
Testing climbing slings involves a whole lot of going climbing. For this review, we tested slings side-by-side on long multi-pitch routes in Red Rocks and Eldorado Canyon, as well as in the alpine rock climbing paradise of the Bugaboos in British Columbia. This testing allows us to get a feel for the strengths and weaknesses of each product, and to notice what we like and don't like about them. We also conduct extensive internet research, attempting to identify what other climbers like and don't like, then evaluating these perspectives ourselves. To put products on the spot, we most frequently went out to our local climbing area of Smith Rock, to play around on the traditional cracks of the lower gorge, or the bolted multi-pitches on welded tuff. Lastly, we perform side-by-side tests, such as weighing all products on the scale and tying and untying knots after weighting them, so we can most closely notice the subtle differences between the performance of each one. The end result is this exhaustively researched, heavily considered, and carefully tested review.
Related: How We Tested Climbing Slings
Analysis and Test Results
Climbing slings are loops of webbing that are sewn together using a special bar tacking machine, and are rated to a minimum force of 22kN (or 4,945 lbs.). Slings are generally made out of two primary fibers: Nylon, which was the most common until the late 1990s, and Dyneema, a modern thermoplastic fiber made of polyethylene that is among the strongest known to man. Dyneema is a brand name, and while there are numerous other fiber types with different names also included in this test (i.e. Spectra, Dynex), they are all extremely similar in their characteristics and are all made with high-molecular-weight polyethylene. Sometimes we will simply refer to all of these different fiber types as Dyneema. Slings come in many different lengths for different purposes. The most commonly used length is 60cm (or 24"), which is commonly referred to as "shoulder-length," and most frequently used to extend a piece of climbing protection to reduce rope drag on the leader. Another popular length is 120cm (48"), a "double-length" sling that is most frequently used for equalizing multiple pieces of protection in an anchor. While these are the most common uses for slings, only your creativity can limit the potential they have while climbing.
Related: Buying Advice for Climbing Slings
For this review, we tested the majority of the slings in single-length, while a couple that seemed to have characteristics that would flourish for anchor building we tested in 120cm length. We tested and rated each sling for five different metrics that affect a sling's performance: Handle, the Knot Test, the Alpine Quickdraw Test, Weight, and Bulk. Each of these metrics, including why they matter, how we tested for them, and which slings were the top performers, are described in greater detail below. In all cases, slings were rated compared to the competition, so if a sling received a low score, it doesn't mean that it is not capable of that function, but rather that it performed worse than the others we compared it against. Some products with lower scores, for instance, the two cord slings that we tested, have very compelling reasons to buy them, despite not being the highest scorers. Although the scores are a handy tool, we encourage you to think carefully about your own specific needs.
An important consideration with any product is value. We don't score value, but also don't want to leave you in the dark when it comes to figuring out where your money might be best spent. In general, we found that the price of Dyneema slings is closely bunched together, with little differences in cost between different companies. For these, the best value will clearly be to choose the slings that performed the best. For the best overall value, however, the wisest move would be to look to Nylon slings. These generally cost less than half of the average Dyneema sling, which could allow a new climber to outfit themselves with a large selection at a considerable savings.
Handle is a term that is often used to describe the feel of a climbing rope in one's hands, and we use it here to assess slings with pretty much the same meaning. Think of handle as how comfortable or friendly a sling feels as it slides between your fingers, as well as whether it is soft and pliable or rather stiff and electrical cord-like. Although this criterion is mildly subjective, we can surely all agree that what feels softer and more comfortable to hold in one's hands is more enjoyable to use on a daily basis or in repetitive situations than something abrasive, rough, or stiff. Handle, then, is an assessment of which slings feel the best as we are using them.
Most of our assessment for handle came from using these slings repeatedly on long multi-pitch rock climbs, noticing along the way which ones were the most enjoyable, and which ones struck us as less friendly to use. We also compared them side-by-side on the ground, taking notes about how they feel as they slide through the hands, whether they have abrasive or smooth edges, and how smooth and low profile the bar tacking is.
In the end, three slings simply feel nicer than the rest, although the scores for all of these products ended up fairly bunched together so it is hard to definitively declare some slings as superior to others. The Mammut Contact Sling, is the lone Dyneema fiber sling that we feel is friendlier than the others. However, both of the Nylon slings we tested — the Black Diamond Nylon Sewn Runner as well as the Sterling Nylon Sewn Runner — also scored at the top for handle. Nylon is just softer, slipperier, and more comfortable in the hands, without any rough edges, and is also supremely supple, making these slings a top choice if handle is a priority. As one of the more important characteristics to the performance of a sling, we weighted it as 25% of a product's final score.
In the majority of climbing situations, a sling will be left un-knotted to slide freely through a carabiner. There are also countless other situations, however, one might want to add a knot to a sling, such as when building and equalizing anchors. When it comes to knots, and especially untying them, not all slings perform the same. Compared to climbing ropes, slings have a propensity to become "welded" after being weighted, which essentially means they cinch up so tight that you can't get them untied. To assess and describe how easy it is to tie and untie knots in a particular sling, we performed some knot tests.
The two most common knots that climbers tie in their slings are the figure-eight on a bight and the clove hitch. We tied each of these slings into these knots on the same carabiner, then weighted them, to see how tight they got and assess their relative ease of untying. As a relatively simple knot, the clove hitch rarely presented any sort of problem to loosen and untie — simply wiggling it back and forth a few times is usually enough to loosen it so it can be untied. The figure-eight, however, is a whole different story. As any climber who has taken a lead fall on a climbing rope knows, this knot can cinch up very tight, and with so much friction built-in, it can be very hard to untie. How easy this knot is to untie became the predominant factor in a sling's score for this metric.
Our testing reveals that the thickest Nylon slings, as well as the very thinnest Mammut Contact Sling, present the most difficulty once a knot has been weighted. If you are in a hurry to move on from your belay when it's your turn, be sure to think carefully before you incorporate figure-eights tied into these types of slings. On the other hand, there is a sweet spot among the medium-width Dyneema slings, that seemed to show they can be tied into knots and untied easier than those just described. The easiest slings for this are the Metolius Open Loop Sling and the Camp USA 11mm Express Dyneema Runner, making them excellent choices for use at anchors. These two slings are stiffer and flatter than many of the others, which prevents them from welding so tightly together, and allowing for much quicker untying when leaving the belay. The absolute easiest slings to untie once they have been knotted and weighted are the two cord-style slings. In particular, the Edelrid Aramid Cord Sling, with its tightly woven 6mm construction, is simply a breeze to untie once it has been knotted. The Knot Test accounts for 25% of a product's overall score.
Alpine Quickdraw Test
Climbing slings are long and dangly and this can present a bit of a problem when it comes to carrying a bunch and trying to avoid them getting caught up in all your other gear. Draping them over one shoulder and around the neck is a common solution to this problem, but even more popular is the alpine quickdraw. An alpine quickdraw is a shoulder-length sling that has been shortened by tripling it up with a carabiner on each end so that it is roughly the same length, and functions in the same way, as your average quickdraw. It also allows slings to be easily racked on harness gear loops, which can make them easier to access and deploy quickly mid-lead than unslinging one that is wrapped over your neck and shoulder. By removing the carabiner from the free-hanging end, then re-clipping it into only one strand of the tripled sling and pulling, you can switch quickly from an alpine quickdraw to a full-length runner ready to clip to the rope.
For this test, we took each sling and repeatedly tripled them up into alpine quickdraws, then released them again into full-length slings, and rated them based on how well they performed this task. We deducted points for any hang-ups or issues we encountered. Two main factors dictate how easy it is to form or extend an alpine quickdraw. First is the width and bulk of the sling. Wider slings are more likely to overlap each other when tripled up in the crotch of a carabiner, creating friction and often preventing the sling from equalizing its length when forming the quickdraw. The second is the length and bulk of the bar tack, which varies from sling to sling, despite equal strength requirements. Longer and bulkier bar tacking have a greater propensity to hang up on one of the two carabiners, which can once again prevent the sling from equalizing itself when pulled taut into an alpine quickdraw.
It should come as no surprise that the top performers for this category are the thinnest slings that have the lowest profile bar tacking. Once again, the Mammut Contact Sling, at a mere 8mm of width and featuring an innovative bar tacking pattern that is the lowest profile of all those tested, is the top performer. The very light and narrow Petzl Pur-Anneau Sling and the Sterling Dyneema Sling, which includes a small bar tack covered in a rubberized plastic cover to eliminate sewn tabs that can hang up on carabiners, are the second-highest performers in this category. Despite other solid advantages, the two cord slings performed the poorest at this task. In particular, the Beal Dynamic Sling, with a diameter of 8.3mm, is borderline too fat to easily fit through the carabiners, and also won't hang down straight once tripled up. This test accounts for 20% of a product's overall score.
Slings are simply single loops of thin webbing, so as you might expect, they are very light pieces of gear. Compared to the weight of a pair of shoes, a cam (or a whole rack of cams), or even a locking carabiner, slings present what may seem to be an insignificant weight while climbing a route. However, we believe that no opportunity to cut weight while not compromising on performance should be overlooked, especially when climbing, because every single thing on your body has to be held by your fingers. Since you can buy lighter slings that are equally as strong as heavier ones, why wouldn't you?
Let's be real, though, and admit that we don't think the weight of your slings is going to be the deciding factor between sending a big route or not. In fact, to be able to tell the difference between these slings most precisely, we had to weigh them in grams rather than ounces. At times there was only a difference of 1g between different slings, and even if you multiplied this difference by 10 (for the number of slings you might carrying on a route), 10g in the best case, or 190g if comparing the lightest to the heaviest (19g x 10 slings), is still only a difference of .35oz to 3.17oz, depending on which slings you choose to buy. Worth pointing out is that weight is one of the key advantages a Dyneema sling over a Nylon one, as Dyneema is significantly stronger at the same weight, meaning for a comparable strength sling, they can be far lighter and thinner than Nylon.
To determine a sling's weight, we ignored what the manufacturers published on their websites and instead weighed each sling on our independent scale immediately upon receipt, before we used them and any dirt had a chance to impact the results. We found the Mammut Contact Sling to be the lightest at a mere 19g, although this was a fair bit heavier than the 14g figure quoted on Mammut's website, a discrepancy that we can't explain. Also weighing in at 19g is the Petzl Pur-Annueau Sling, while the Black Diamond Dynex Runner and the Trango Low Bulk 11 Sling are only 1g heavier, weighing in at 20g. The heaviest slings are the ones made out of cord, with the Edelrid Aramid Cord weighing in at 43g, and the Beal Dynamic Sling weighing a whopping 78g. These cord slings offer specific advantages to help you see past their extra weight, and regardless we would likely only carry one (Beal) or a few (Edelrid), at most anyway. Weight accounts for 15% of a product's final score.
Due to differences in fiber and the pattern of the weave, different slings come in different weights, thicknesses, and shapes, even though they are all of equal strength. The width of the slings that we tested ranges from 8mm on the small end, up to 18mm on the larger end, and 6mm to 8.3mm when talking about cord. Some slings are made of a flat piece of webbing, while others are tubular in shape, which means they are thicker. Bulk assess for how small and compact a sling can be.
Bulk is similar to weight when it comes to deciding how important it really is. On the one hand, the difference between a fat sling and a very thin sling, even when you multiply it out by an entire rack of 10 or so slings, is not very significant, simply because we are talking about thin strips of webbing here. But on the other hand, if you consider the differences in terms of percentage, then a Nylon 18mm wide sling is well over 200% as bulky as a super-thin Dyneema sling, and if you have the opportunity to purchase something that is less bulky without compromising on performance, then why wouldn't you? Less bulky slings will pack down smaller in your approach pack, take up less space racked together on your harness, and also slide over carabiners easier as you deploy them.
To assess for bulk, we started by comparing the widths of each sling, and then also factored in their thicknesses, which often has to do with whether they are of flat, tubular, or cord designs. Less bulky slings score higher for this metric. Once again, the Mammut Contact Sling is the least bulky, as its 8mm width is two millimeters slimmer than the next closest competitor, even though it is of tubular design, which almost negates the differences. The Black Diamond Dynex Sewn Runner and the Petzl Pur'Anneau Sling are very close seconds when it comes to bulk, and received the second most points. The Nylon options we tested, which need to be around 17mm wide to be equally as strong as the much thinner Dyneema options, are of course bulkier. Bulkiest of all are the cord slings, especially the Beal Dynamic Sling, which is as thick as a piece of climbing rope, and is also rather stiff. Bulk accounts for 15% of a product's final score.
Climbing slings are an essential part of every climber's rack and come in a surprising array of choices considering how simple a piece of gear they are. While any sling that you choose to buy will perform the job well, we feel there is no reason not to select the very highest performing ones if you have the chance. In general, Dyneema slings offer the best combination of performance and weight, but will cost you more. Nylon slings are a good alternative if you need to save some cash. Cord slings are great for specialty purposes, and having one or two on your rack can really help, but you wouldn't want an entire set of them. We hope that we have helped make your sling purchase easier and led you towards the best product for you. We wish you happy climbing!
Related: Buying Advice for Climbing Slings
— Andy Wellman