Sub 9mm Climbing ropes

Comparison Review: Sub 9mm Climbing Ropes

Sub 9mm Climbing Rope Comparison

It wasn’t very long ago that people looked to 10mm beasts of a rope for an everyday workhorse and ropes under 9mm in diameter were few and far between. Well that’s no longer the case with 5 different options currently on the market and undoubtedly more to come. Companies like Sterling, Petzl and others already have 9.0mm ropes available and even more companies have options in the 9.1mm area.

Sub 9mm Climbing Rope
Our line-up of Sub 9mm Climbing Ropes. From left to right: Edelrid Canary, Beal Opera, Mammut Serenity, Black Diamond 8.9mm Dry and Edelrid Swift Pro Dry.

Now with all these thin cords available it can be harder to pick one. Which is the best for ice climbing, for long alpine link-ups or for sending projects? Well the table below summarizes the details of each rope and is followed up by a brief review of each rope which wraps up with a summary of their respective pros and cons. The line-up includes:

  • Edelrid Swift Pro Dry (will also comment on the Eco Dry version)
  • Edelrid Canary
  • Beal Opera
  • Mammut Serenity
  • Black Diamond 8.9mm Dry

Of course it goes without saying that all of these thin ropes are very specialized tools and should be used with caution.

Sub 9mm Dynamic Climbing Rope Comparison Table:

Sub 9mm Climbing Rope
* If used as a single rope

Edelrid Swift Pro Dry 8.9mm:

Edelrid Swift Pro Dry
Edelrid Swift Pro Dry. The middle mark on the Swift is a double black dash. Easy to see though it is fading. The Eco version has the same middle mark while the CT version has a weave change making it a great option for multi-pitch routes.

One of the more established ropes in the review, Edelrid’s Swift comes in three different models: Swift Pro Dry, Swift Pro Dry CT & the Swift Eco Dry. They’re all basically the same rope just with different features. The CT model has a mid-rope pattern change, a great option for multi-pitch and alpine climbing. The Eco version on the other hand is the first PFC-free rope that meets the UIAA standards for a dry rope and the sheath is made from yarns leftover from making other ropes. And, like the Boa Eco, this gives it a very cool and distinctive look.

Edelrid Swift Pro Dry
A belay stance while testing out the Swift Eco Dry.

Looking over the spec’s I found it interesting that the static elongation is quite high at 9% while the dynamic elongation is more average in the low 30’s. This means that the rope stretches quite a bit when someone sits on the rope though it’s not overly stretchy in a lead fall. Of course this results in slightly higher impact forces but nothing of significance, we’re just talking about a few decimal points. Besides it’s not designed for top roping anyway, none of these thin cords are.

As with all Edelrid ropes, the Swift comes wrapped in a circular coil but the packaging has a small hole that’s used to uncoil the rope with a minimal amount of twisting. Not quite as nice as ropes that come lap coiled but definitely a close second!

Edelrid Swift Pro Dry
Damaged Swift

In preparation for this article I grabbed a Swift Eco Dry as my climbing partner had recently purchased the regular Swift Pro Dry. I figured that this would give me the opportunity to compare the two head-to-head to see what the differences might be given the different dry treatment, etc. Alas this was not to be as I dropped a rock on the Swift Pro Dry on the 6th pitch of a climb on the very first day of testing. That ended the comparison review idea! If you’re wondering, no I don’t think the damage to the rope would have been any different with a larger diameter cord. It was pinched when a rock fell on the rope stack cutting through about half rope. Just a little bad luck mixed with some poor rope management.

The Swift feels a little stiff right out of the package, as do many dry ropes, but it loosed up nicely after a few pitches of climbing & belaying. The dry treatment on the Swift Pro Dry gives the rope a nice smooth feel without being overly slippery. On the Eco Dry it has a slightly different feel, almost soapy. Belaying with the Swift, as with all thin ropes, is an absolute pleasure as the rope feeds though a belay device smoothly. Of course a little extra care is needed when belaying or rappelling on a thin cord as they don’t generate as much friction.

Pros: Solid and supple climbing rope, ecofriendly & mid-rope pattern change options avail.

Cons: Not as durable as some of the other thin ropes

Overall: A great option for multi-pitch and alpine climbing or as a light rope for sending your project. The readily available color options through the various versions also make it great for climbing in a group of 3 or for use as double ropes.

Edelrid Canary 8.6mm Dry Rope:

Edelrid Canary 8.6mm rope
Edelrid Canary 8.6mm rope. The middle mark on the Canary is an easy to see double black dash.

In addition to the 3 different Swift variants, Edelrid also makes an even thinner rope. The 8.6mm Canary. The only company to have more than one sub 9mm climbing rope on the market Edelrid is definitely a force to contend with in the thin rope market.

Despite being one the thinnest options on the market the Canary’s amazingly durable. This was done by making the sheath thicker, an amazing accomplishment on such a thin rope. And really, what causes you to retire a rope? For me it’s almost always the degradation of the sheath. To through some numbers at it, the Canary’s sheath proportion falls in at 47%. Way above the mid-to-high 30’s of the other ropes.

 Edelrid Canary 8.6mm rope
Putting the Edelrid Canary through the paces at the crag.

With the thicker sheath the Canary actually feels burly. It has the stiffest hand of all the ropes reviewed for this article though it’s far from the stiffest rope I’ve used in general. When stacked on the ground in preparation for a climb the Canary doesn’t lay flat and it feels more like a normal climbing rope when belaying. Not as slippery as some of the other options. And of course stiffer ropes are generally less prone to tangling but knots need a little more dressing.

While Edelrid’s website states that they make a pink version of the Canary I’ve only ever seen the green in stores. Unfortunately this makes it hard to use them as double ropes or for climbing in a group of three.

As mentioned in the Swift write-up, Edelrid ropes come wrapped in a circular coil but the packaging has a small hole that’s used to uncoil the rope with a minimal amount of twisting. A great solution to a common problem.

Pros: Very durable, easy to use.

Cons: Only the green version is easily found.

Overall: A fantastic all-round climbing rope. The durable sheath allows the Canary to stand up to punishment at the crag, multi-pitch rock climbing, alpine climbing, etc.

Beal Opera 8.5mm Dry Rope:

Beal Opera 8.6
Beal Opera 8.6.

The Beal Opera 8.5 is the lightest and thinnest single rope on the market! The only rope available at less than 50g per meter and at 8.5mm in diameter it looks the same as a lot of half ropes. That being said, it also features some cool innovations like Beal’s UNICORE technology to improve safety around sharp equipment or rocks.

Beal Opera
The Blue Beal Opera 8.5 Rope getting a few laps on some rock in Squamish.

While it didn’t hit the market in North America with much fanfare this rope, and the Unicore tech in general, is a game changer! One of the biggest dangers in climbing is damaging or cutting a rope: sharp edges, falling rocks, crampons, etc. can all lead to a rope failure which can catastrophic in a single rope system! What has been coined as UNICORE tech is basically a thin membrane that’s placed between the core and the sheath.  This membrane bonds the sheath and the core together while still allowing for the rope to stretch under load.  So what does it mean?  Well basically if you damage the sheath, the rope will still function as designed instead of potentially breaking!  Of course this doesn’t mean you should continue to climb on a damaged rope!  To really get a feel for the difference check out this video clip:

The Beal Opera 8.5 is supple, smooth and easy to belay with… well almost too easy to belay with really!  I used the Edelrid Mega Jul belay device with the Opera as it handles thin ropes exceptionally well.  I’m sure that a Petzl Reverso 4 would also do the trick as well.

Beal Opera
Topping out on a mixed climb on the Chief over Squamish, BC with the green 70m Beal Opera 8.5.

Unfortunately Beal’s ropes come wrapped in a circular coil and the Opera is no exception. This means that the rope’s basically pre-twisted and care has to be taken unrolling the rope to avoid a tangled mess.

As a very thin and triple rated rope the dynamic elongation, basically how much the rope stretches in a fall, is quite high at 37% (most ropes are in the low 30’s). The upside to this is a very low impact force in a fall. The down side is the additional distance traveled while falling requiring extra caution off the ground, over ledges or above other climbers.

Pros: Supple, lightweight, very resistant to sheath failure

Cons: Hard to find, very stretchy, packaged in a circular coil

Overall: A fantastic option for ice climbing where the extra stretch doesn’t really matter and Unicore tech adds an additional margin of safety around all the sharp equipment. It’s also a good alpine and rock climbing rope though not as durable as some of the other options and the extra stretch is more of a concern.

Mammut Serenity 8.7mm Dry Rope:

Mammut Serenity
Well used blue and green Mammut Serenity ropes. The blue rope has a new middle mark while the green one is quite faded and in need of a refresh. If you’re curious how I mark mine you can check out the article here.

This rope is the Old Dog of the pack and was the smallest single rope on the market for a while before getting beat out by the Canary and Opera. It’s a rope with a proven track record and the go-to for many professional guides as well as recreational climbers and alpinists when it comes to skinny ropes.

The Serenity doesn’t really stand out in any one review category but rather does fairly well across them all. It has low elongation or stretch values but the impact forces are still fairly low as well. Combined with a decent sheath proportion, the Serenity is also decently durable. Better than the Swift but not as good as the Canary. Just a solid all-round rope.

Mammut Serenity
Testing the Mammut Serenity 8.7mm rope on a long alpine traverse.

Little details can go a long way with gear. They show attention to detail and a willingness to innovate. Mammut’s ropes come lap coiled and ready to go right out of the package. A really nice feature that makes putting the rope into service easy and pain free. Another great feature is Mammut unique tag. Instead of using a plastic cap or tight wrap that might get stuck in a crack or when rappelling they instead use a supple iron-on type label.

The middle mark on the Serenity is the standard black dash. This works great on the green version but is a bit harder to see on the blue when it starts to fade.

The Serenity has a fairly supple hand and good feel. It’s easy to belay, isn’t overly slippery and stacks nicely. While I’ve found that the performance and feel of some Mammut ropes can vary from year to year, I’ve used several Serenity ropes over the last 5 years and they’ve been nicely consistent.

Pros: A solid all-round performer, widely available in 2 colors.

Cons: Generally the most expensive option

Overall: A great generalist of a rope with a long proven track record that easy to find in both blue and green colors.

Black Diamond 8.9mm Dry Rope:

Black Diamond 8.9mm Dry Rope
Black Diamond 8.9mm Dry Rope with a slightly worn middle mark.

BD’s 8.9mm Dry rope may be the new kid on the block when it comes to sub-9mm single ropes but this exceptionally bright pink rope is hard to miss anywhere. Strangely Black Diamond has resisted naming any of their ropes preferring instead to simply refer to them by diameter. But with or without a name the new 8.9mm Dry rope is a solid choice that offers exceptional value.

The 2018 version of the Black Diamonds ropes are a totally different animal than the previous versions. Why? Well BD changed manufacturers for 2018 which has drastically improved the product. So if you’re steering away because of a bad experience in the past you may want to look again.

Black Diamond 8.9mm Dry Rope
It’s hard to miss this exceptionally bright rope anywhere.

The BD 8.9 is one of the most supple ropes in this review, much like the Beal Opera. This makes it easy to tie into and easy to climb with but almost too easy to belay with. I found that the regular ATC Guide didn’t really provide the friction I wanted and so tended to use a GriGri+ or a Reverso to belay and rappel. Of course the new ATC Alpine Guide will be ideal when it comes out.

The Dry treatment on the rope gives it a bit of a soapy or almost tacky feel, similar to the Swift Eco. It didn’t seem to attract dirt or debris in any way so I can only assume the feeling is caused by some moisture on my hands.

Black Diamond has followed Mammut in packaging their ropes lap coiled and ready to use. And it’s really nice when a new rope doesn’t come pre-twisted!

The middle mark on the 8.9mm rope can only be described as terrible. It’s also much different than the middle mark on other BD ropes that I’ve climbed on this year. It doesn’t seem to be created with a die so much as a thin black coating on the rope that binds in a GriGri and flakes off in the hand. I will have to apply a better middle mark as the stock mark disappears.

Pros: Inexpensive, bright

Cons: Shitty middle mark, only available in one color

Overall: A solid rope at an absolutely great price, definitely worth checking out.


Some of these ropes were provided for review but of course this did not influence us in any way. We call’em like we see’em.