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Sterling Nano IX Review

This "experts-only" rope was our favorite option for long sport routes
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sterling nano ix climbing rope review
Credit: Sterling
Price:  $329 List
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Manufacturer:   Sterling
By Cam McKenzie Ring & Andy Wellman  ⋅  Dec 2, 2021
  • Handling - 35% 6.0
  • Durability - 25% 6.0
  • Weight - 20% 10.0
  • Catch - 20% 7.0

Our Verdict

The Sterling Nano IX is one of the lightest and thinnest climbing ropes in our test group, measuring up at a slim 9.0mm. While there are other specialty twin and half ropes (and even a couple of singles) that are thinner and lighter, the Nano IX slightly thicker diameter provides just the right amount of confidence. It is a specialty line, which we explain below, and should only be used by those with a lot of experience belaying. It's also not an everyday cragging workhorse rope, though we did use it as such during our testing period to gauge its durability. We used it for long and winding 35-meter sport routes where we took some big whippers and then yarded ourselves back up again, and it withstood that abuse to our satisfaction and met our expectations. This is a quiver rope, meaning it is only appropriate in certain situations and for certain days, such as sending strenuous sport routes or long multi-pitch adventures where every ounce matters. It is also best used only by experienced climbers--be sure to check the belay device you are using to be ensure it can handle this rope diameter.
Great handling for a thin line
Rated as a single
Half and twin
Not as durable as a thicker rope
Just the Nano IX now
This rope used to be known as the "Fusion Nano IX," but Sterling has dropped the "Fusion" from the name. If you see this as part of the name, then perhaps you can get this rope at closeout prices. However, the Nano IX is essentially the same as the older version with the old name.

Our Analysis and Test Results

We need to take a moment before we start this review to mention that thin lines like the Nano IX, the Edelrid Swift Eco Dry, and the Beal Joker are for experienced climbers only. These specialty lines serve a great purpose for those looking to move fast in the mountains or send a hard and long sport route, but they are more difficult to use than the "thicker" ropes in this review. Even our experienced testers found it a little more worrisome to catch a big fall with these lines. Not all active assist belay devices will grip one of these super-thin ropes, so check yours before you belay with one. They will also not last as long as a thicker rope and are more expensive, so they are not intended for everyday use. Sterling even has the following warning on their website: "Due to the Nano's small diameter, it is recommended that it only be used by experienced climbers and belayers and NOT for top-roping or working of routes. It is critical that proper belay devices be used and extreme caution should be taken."

The Sterling Nano IX is a 9.0mm rope that weighs 52 g/m, making it one of the thinnest and lightest lines in this review. It is rated for single, twin, and half use, and it's available at standard intervals up to 80m.

Performance Comparison

sterling nano ix climbing rope review - testing out the nano ix at smith rock, or. this lightweight line is...
Testing out the Nano IX at Smith Rock, OR. This lightweight line is great for long sport climbs where you want to lighten up as much as possible, but it should only be used by experienced climbers and belayers.
Credit: Andy Wellman


The Nano has great handling out of the box, without feeling too slippery or slick. Sometimes the dry treatment that a manufacturer uses can end up leaving what feels like a slick residue on the surface of the rope, but we didn't notice it with Sterling's DryXP treatment (a UIAA-certified treatment that prevents less than 5% water absorption). The Nano IX continued to have great handling throughout our testing period, though right towards the end (around the 80 pitch mark), we noticed that it was starting to stiffen a little. A quick trip through the washing machine solved that problem, and it continued to handle better than the similarly thin and lightweight Beal Joker.

sterling nano ix climbing rope review - we liked the handling on this line, particularly when making fast...
We liked the handling on this line, particularly when making fast clips on a sport route.
Credit: Cam McKenzie Ring

That being said, it is still a skinny line, and it's generally harder to control in a belay device compared to a thicker 9.7-9.8mm rope, which is why its overall handling score is lower than some other models in this review. Gloves help with this a lot, as does experience. Be sure to look at your belay device carefully and consult the specs. Petzl's newest GriGri and GriGri+ can accommodate ropes down to 8.5 mm and should help give you more peace of mind when branching into the skinny rope world.

sterling nano ix climbing rope review - we had no slippage issues when using the nano with a grigri 2 and it...
We had no slippage issues when using the Nano with a GriGri 2 and it certainly fed better through that device than a thicker 10mm rope, however, it is more challenging to belay with a skinny rope as they are generally harder to hold on to when arresting a fall and lowering your partner. Wearing gloves helps.
Credit: Scott Ring

On a final note, the middle mark on the purple line that we tested was almost impossible to see, and it wore off quickly. If you need a distinct middle mark for frequent rappels, consider a lighter color or even better the bi-pattern option.


We didn't notice anything particularly hard about the catch on this rope, other than we always hoped our belayer was holding on tight! The Nano IX doesn't have quite as much elongation as most of the thicker lines that we tested (26% vs. the 38% of the Beal Booster), but that wasn't always noticeable in a real-world fall scenario with a dynamic belay.

sterling nano ix climbing rope review - falls felt great on this line as long as there was sufficient slack...
Falls felt great on this line as long as there was sufficient slack out. We did notice a bit of stiffening after the 80 pitch mark though.
Credit: Cam McKenzie Ring


Here is where the Nano IX beat all of the other models. At only 52 g/m, it is easily one of the lightest lines in this review, tying the Edelrid Swift Eco Dry for that honor. But what does that mean for you? A 70-meter length of the Nano Ix should weigh around 8 pounds, which is almost 2 pounds less than a 62 g/m workhorse rope. That difference is certainly noticeable in your backpack, as well as at the top of a long pitch. However, that weight savings comes at the cost of the next metric: durability.

sterling nano ix climbing rope review - this rope is so light and thin that the 70-meter version that we...
This rope is so light and thin that the 70-meter version that we tested weighed about the same at the 60-meter version of the thicker ropes in this review. That difference was appreciated on long hikes into a long route.
Credit: Scott Ring


When compared to the other lines in this review, there's no question that the skinny ones are less durable in the long term. While a thicker "workhorse" rope could last you for years if you put the same cragging and top rope use on one of these it probably won't. That's because most ropes get retired due to sheath damage and there's less sheath material as a percentage of the overall rope (only 29% for the Nano compared to high 30's and low 40's for thicker lines). We did treat this line like a cragging rope and have to say that we were impressed with how much better it looked than the Joker after about 80 pitches. The Nano's sheath did have some "glazed" sections though. We prefer the Nano for sport cragging if you insist on going skinny. That said, our favorite choice for sport climbing on a skinny rope is the Edelrid Swift Eco Dry, so be sure to take a look at that one as well if you are purchasing a long send line.

sterling nano ix climbing rope review - this rope was still looking great after 80 pitches, with only little...
This rope was still looking great after 80 pitches, with only little "glazing" and minimal fraying. However, the middle mark dissapeared on us!
Credit: Cam McKenzie Ring

Note that we heard a lot of anecdotal reports (and read some online as well) about these thin lines getting a core shot on the first pitch of XYZ after getting stuck behind a flake etc., etc. Is this necessarily the rope's fault? A 10mm line might have had the same issue in the same situation. While our durability testing is not exactly lab conditions, we do strive to put the same amount of wear on all the ropes we test on the same types of rock.


There's no doubt that this is an expensive rope, and considering you won't want to use it for all of the various situations that you could use a thicker rope, its overall value is suspect. Beyond that, thinner lines like this one surely won't last as long as a thick workhorse, which may also be cheaper. What we're saying is that this is not the rope for you if you are on a budget, and should be a specialty rope for experienced climbers who know they need it. Compared to the other skinny ropes we've reviewed, it's not the most expensive nor the least, and we think it affords pretty decent value for its specific purpose.

sterling nano ix climbing rope review - staring down the impending crux on an onsight attempt of glory daze...
Staring down the impending crux on an onsight attempt of Glory Daze, a 35-meter wandering 12c at the Robber's Roost, NV. This rope is great option for these situations, and anytime where a lightweight line could make a big difference.
Credit: Cam McKenzie Ring


We like a lot of things about the Sterling Nano IX. It's lightweight, handles well, and it fared pretty well during our tests. This is a great rope for certain situations, like a hard onsighting on a long alpine route, but it's not the best everyday cragging rope. The new DryXP treatment also makes it suitable for mountaineering and ice climbing, though the rise of the Unicore lines has us often opting for those in many situations due to the extra bit of safety that their interconnected sheath and core provide. The Nano is still a great line though, and we'll be bringing it out for those backcountry routes that goes on forever.

Cam McKenzie Ring & Andy Wellman

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