NUGGET #1 – the Petzl PUR’LINE


This is the first iteration of something I’ve been thinking of starting for a while. The purpose of these “NUGGET” posts will be to share some bits of climbing/mountaineering equipment that I feel are exceptionally good/functional/useful, with some explanation of why I think they are so good. My primary motivation is simple: to keep these exceptionally good products available. Sadly, the best, highest-performing products are often the ones that don’t sell well enough, and are discontinued within a year or two of going on the market. Sometimes that is because a product is simply very niche, and only relevant to a small group of people. However, I think that more often it is because it takes time for a significant number of people to catch on to how good some products are.

A second motivation is just that it is satisfying to provide people with helpful information. A third motivation is that when the piece of gear I’m endorsing happens to be made by one of my sponsors, that sponsor will hopefully appreciate my taking the time to promote that piece of gear. However, I ABSOLUTELY PROMISE that I will only write these NUGGET endorsements for gear that I honestly think is awesome. I have never endorsed a product that I don’t personally believe in (even though I’ve been asked many times to do so), and I never will. Honesty is too important to me, and it is too important to me to not erode my credibility. When one of these NUGGET endorsements is of a piece of gear made by one of my sponsors it is not coincidence, however – I am a gear nerd through and through, and I have sought out the sponsors that I have specifically because I want the best gear for my own climbing/mountaineering. Certainly, many of these NUGGET posts will be pieces of gear that are not made by any of my sponsors. The only aspect of these posts that will be affected by my sponsorships will be the omission of some NUGGET posts that I might otherwise make. For example, even if I thought that the Black Diamond Raven Ice Axe was really awesome (I definitely don’t – it’s just a random example of a piece of generic climbing gear), I nonetheless wouldn’t make a NUGGET post about it, because it is a product that directly competes with ice axes made by Petzl, one of my main sponsors.

Anyways, without any doubt, the overwhelming limiting factor to how many of these NUGGET posts I make, or how often I make them, will be finding the time in my too-busy life to write them!

PETZL PUR’LINE – The best rappel rope for lightweight alpine climbing

Sometimes in alpine climbing it is only necessary to carry one rope, and that is always nice. However, very often the wise decision is to carry two ropes, and then the obvious choice is between a pair of twin/double ropes, or a single rope and a rappel rope. A pair of double ropes is often the best choice if climbing moderately difficult terrain as a group of three climbers. Whether two or three climbers, a big advantage of using a pair of twin/double ropes is that rappelling with two ropes of the same diameter is very smooth and simple. However, there are a bunch of advantages of pairing a single dynamic climbing rope with a rappel rope:

  • 1) It allows for hauling, if so desired.
  • 2) It allows for the follower to easily ascend the rope directly, if so desired.
  • 3) It allows for the best simul-climbing techniques. The advent of the Petzl Microtraxion has significantly increased the difficulty of terrain that I am comfortable simul-climbing on. Using Microtraxions to safeguard against the follower pulling off the leader works best with a single rope (although it is also possible with twin/double ropes).
  • 4) It allows for the use of certain rope devices, like a Grigri, that don’t work with twin/double ropes.
  • 5) It makes for less rope-drag. This may sound surprising to some people, because many people advocate the use of double ropes specifically to reduce rope drag. There are specific scenarios where double ropes can result in the least rope drag (pitches that are extremely wandering AND very difficult for the climber), but 90% of the time I find that using a single rope results in the least rope drag.

For all these reasons, a single rope and a rappel rope is usually my preferred system when alpine climbing with two ropes, and I have used this rope system A LOT, starting around 2002 with my main climbing partner at the time, Mark Bunker. At first we just bought 60m sections of 6mm accessory cord. We did this mostly because it was cheap, but also because there was extremely little selection at the time of lightweight rappel ropes. Using 6mm accessory cord is very unideal for a number of reasons: It is very supple (and thus tends to get tangled with itself, and caught on the rock), it stretches A LOT, and most of all because it is really not very strong or cut-resistant. Nonetheless, Mark Bunker and I used this system on a bunch of good climbs together, including the second ascent of the Waddington Traverse, in 2004.

Eventually, I found a way to buy the 5.5mm Maxim “Tech Cord” in 60m lengths (23.6 g/m by my measurements). This was a massive improvement from 6mm accessory cord. It is quite stiff, which makes it much less likely to get stuck on the rock when pulling down the ropes. More importantly, it is very strong, and very cut resistant. The biggest downside to using the Maxim Tech Cord as a rappel rope was that there was a lot of sheath slippage. I used the Maxim Tech Cord as my rappel rope for many years, for climbs such as the first complete ascent of “Los Tiempos Perdidos” on Cerro Torre (2007), and the first winter ascent of Mt. Huntington (2007).

The next improvement in my rappel ropes journey was discovering the SAPER (“six millimeter alpine personal escape rope”) rope, made by Esprit Ropes in Ontario. Esprit Ropes is a small company, and this rope isn’t even listed on their website, so it has to be custom ordered. The SAPER doesn’t use any high-tech fibers (it is pure nylon, as far as I’m aware), but what makes it special is the quality of construction. The sheath is extremely tightly woven, which makes it very durable (for a pure nylon rope), and makes it extremely stiff. The SAPER is so stiff that it can be annoying sometimes (it makes a big coil for a 6mm diameter rope), but overall it is a major advantage. The stiffness makes it much less likely to get stuck on the rock when pulling down your rappel ropes, and as anyone who has done a lot of alpine rock climbing can tell you, that is a huge advantage because getting your rappel ropes stuck is always a major problem. The SAPER is heavier than the Maxim Tech Cord, so for several years I still chose to use the Maxim Tech Cord on certain objectives where weight was more important. In terms of handling while rappelling, the SAPER is the best of any rappel rope I have tried of equal or smaller diameter (obviously an 8.5mm half rope works very well, but is too heavy). If making a huge number of rappels on rock, the SAPER is the best choice if you can justify its weight (31.3 g/m by my measurements), and for certain scenarios I will even still choose the SAPER, even though the more recent offerings from Petzl I prefer the majority of the time. I have used the SAPER on a lot of big climbs, especially in Patagonia, such as the first ascent of the Reverse Torre Traverse (2015).

For a number of years I was sponsored by Edelrid specifically for ropes, and I was involved in the development of their original “Rap Line.” It was essentially a higher-quality version of the Maxim Tech Cord, and made for an excellent rappel rope. Like the Maxim Tech Cord, the original Edelrid Rap Line was about 5.5mm in diameter, with an aramid core, and weighed only a little bit more (25.3 g/m by my measurements). What made the Rap Line much better than the Tech Cord, was a high-quality, tightly-woven sheath, and a core that was braided, rather than straight. The Rap Line didn’t have any of the sheath slippage that the Tech Cord did, and was stiffer, which, as I said before, is a big advantage in rappel ropes. Until the development of the Petzl PUR’LINE (which I’ll get to soon!), this was the best rappel rope I had used, considering all factors (not as nice while rappelling as the SAPER, but much lighterweight). Among other climbs, I used the original Edelrid Rap Line in 2016 to solo Fitz Roy, and then to make the first solo of Torre Egger. Unfortunately, Edelrid pretty quickly discontinued this rope, and the replacements (“Rap Line 2,” and then “Rap Line Protect”), while perhaps better for certain applications, are generally much worse as an alpine rappel rope. The “Rap Line 2,” was much heavier (34.4 g/m by my measurements, so even much heavier than a SAPER), was extremely soft (so it gets caught terribly on the rock when pulling down rappel ropes), and did not handle abrasion well.

Several years ago, Petzl introduced the 6mm “RAD LINE,” using a mixture of nylon, polyester, and high-modulus polyethylene. Perhaps a materials scientist will slightly correct me on this, but high-modulus polyethylene is essentially the same material that we usually know by the brand names “Dyneema” and “Spectra.” Like aramid fibers, it is a high-tech material that is extremely strong for its weight. The RAD LINE weighs only 22 g/m, making it the lightest rappel rope I had ever used when it came out. The biggest problem with the original RAD LINE is that it was a very supple rope, so it was too prone to getting caught on the rock when pulling down a rappel. For this reason, I used the RAD LINE for rappelling on snow/ice/mixed terrain, but not on rock terrain unless it was very steep and clean. Fortunately, last year Petzl updated the RAD LINE, and the newer version is significantly more stiff. The most memorable climb for which I used the RAD LINE as my rappel rope was soloing the north buttress of Begguya, in Alaska, in 2017.

Finally I arrive to the main subject of this NUGGET: the Petzl “PUR’LINE.” This rope went on sale just recently but I have been testing prototypes of it since 2016. I can say without any hesitation that I think this is the best alpine rappel rope ever sold, at least for the criteria that matter to me. The reason it is called the “PUR’LINE” is because it is made purely of high-modulus polyethylene. Because of that material choice, it is extremely lightweight (20 g/m), while also very strong and cut resistant. It is much more stiff than the original RAD LINE, and at least equally stiff as the recently updated RAD LINE (but not as stiff as the SAPER). High-modulus polyethylene is a naturally slippery material, so Petzl put a lot of effort into designing the sheath, to try to maximize the grip. The PUR’LINE would already be the best alpine rappel rope sold simply because of its weight, stiffness, strength, and cut resistance, but there is another surprising advantage: It is incredibly durable. It may be difficult to believe, since it is the lightest rope among all of these that I have mentioned in this article, but the PUR’LINE is by far the most durable among all the rappel ropes I have mentioned in this article. I think that is a consequence of it being made of pure HMPE. I have used the PUR’LINE a lot on my recent trips to Patagonia, and I have been amazed by how little wear it shows after many, many rappels over rough granite. I know that Sean Villanueva was similarly impressed after using one on his recent solo ascent of the Moonwalk Traverse.


  • extremely lightweight (20 g/m)
  • very strong, very cut-resistant
  • quite stiff
  • amazingly durable
  • comes in 65m length, to account for stretch of the dynamic climbing rope


  • expensive
  • not as stiff as the SAPER

PS: It can be quite tricky to rappel with ropes of very different diameters, and these are expert techniques. I could write a lot on this subject alone, but it isn’t the scope of this article. If you’ve never rappelled before with ropes of very different diameters, do some research beforehand and practice the techniques in a low-stress setting before trying it on top of a mountain!