Edelrid Skimmer 7.1mm Pro Dry Half Rope
Earlier this winter I was sent a pair of Edelrid's newest fully certified half/twin rope set, the Skimmer Pro Dry 7.1mm, to demo prior to their North American release and so far I've been very impressed. Having owned about ten different Edelrid models over the years they've long been a staple of my kit. I've climbed on the 6.9mm Flycatcher's for two years now but only certified as a twin their usage is somewhat limited and the Edelrid Skimmer looks to be a viable option for a super lightweight alpine climbing.
The World's Thinnest Half Rope
The Edelrid Skimmer Pro Dry 7.1mm represents a huge advancement in the rope manufacturing industry, making it the thinnest fully rated half rope on the market. The lower limit is presently 7mm for what is possible and by producing the Skimmer 7.1 Edelrid has once again raised the bar for what is possible with modern climbing rope technology.
The difficulty in creating a dual certified rope arises in the standardized testing process. Twin ropes, designed to clip both strands through each piece of protection, are tested identically as a single rope, with a both strands being tested simultaneously with an 80kg weight in drop tower testing. In order to meet the twin rope standard they must be able to withstand 12 drop tower falls, all while staying below 12kN before the initial characteristics begin to diminish.
Because half ropes are designed to be clipped into alternating pieces of protection, they are tested using only a single strand with a 55kg weight. When creating a super thin half rope it becomes increasingly difficult to maintain lower impact forces (8kN) while staying in acceptable the range for dynamic stretch. It would be easy to create a soft catch by increasing the rope elongation in a fall but this means the climber falls a greater distance and increases the risk of decking.
The creation of a certified half in this diameter was made possible through a meticulous fine tuning of the yarn preparation process and the settings on the braiding machines at Edelrid. With more than a century and a half of experience to draw upon, the result was a rope designed to push the limits of modern alpinism.
Weighing in at a scant 36g/m it is one of the lightest ropes on the market and for the 70m ropes I received equates to 2.52kg each. For comparative sake, a Beal Cobra 8.6mm weighs 48g/m equaling 3,360kg each for a difference of 1,680g for the pair. That's about 24 Clifbars you could take with you instead.
The sheath proportion is a respectable 40% but that does mean a substantially reduced core size. Fall ratings at 5 and 18 for half and twin respectively.
Edelrid Skimmer 7.1mm Pro Dry Review
The Skimmers arrived factory lap coiled and ready for use. An unexpected benefit of the thinner ropes is the size. I was able to completely fit a coiled rope completely inside a 35L pack which already contained my complete ice climbing kit. While this seems like a small bonus, it meant less loose coils catching on tree branches or potentially snagging a rock on the approach. They also flaked beautifully and without the propensity to snarl as many thin ropes do.
The Skimmer's are supple in the hand with just enough stiffness to clip one or both strands easily with, or without, gloves. When climbing as a twin they pulled alongside one another with ease. They knotted well and untied easily, even after being weighted. Because no one was willing to whip on an ice screw, we used both strands as a top rope for a day of cragging. Our testers noticed the stretch but also felt the catch was very soft.
Using Edelrid's Pro Dry impregnation methods the Skimmer is compliant with the UIAA Dry Standard by absorbing less than 2% its weight under standardized tests. During usage I didn't notice and change to the handling abilities whatsoever and it didn't appear to take on any water at all.
Belaying and Belay Device Compatibility
It is important to note that at 7.1mm the Edelrid Skimmers are below the stated minimum rope size recommended for use by most modern belay devices. The concern being a lack of generated friction resultant in a loss of control. As such, Edelrid provides a Micro Jul designed specifically for thin ropes. Having used the Micro Jul with my Flycatcher 6.9s and it's big brother the Mega Jul, for quite some time now this was not a shock to me. But I've witnessed a love or hate experience with the assisted braking device. There is definitely a learning curve, particularly in the different method for loading the device in autoblock mode.
We experimented with using conventional devices and found the Petzl Reverso 4, which presently accommodates the thinnest double ropes on the market down to 7.5mm, but could not gain a reliable brake on the ropes without using a second carabiner for additional friction. Using the Black Diamond ATC Guide, which states double rope compatibility to 7.7mm , we were able to manually pull rope through a locked device in autoblock mode. Not exactly confidence inspiring. Interestingly enough, the Kong GiGi belay plate seemed to hold quite well and felt positively airy pulling in slack.
Note: Make sure you always follow the manufacturer's recommendations when using their devices. If you're going to use the Micro Jul, remember that it only comes with one so you'll have to purchase one for your second at approximately $35 CAN.
Rappelling On The Edelrid Skimmer
The thin diameter in conjunction with the Pro Dry sheath treatment meant a slick surface and a fast rappel. Rapping with the Micro Jul in high friction mode means finding the sweet spot allowing the rope to run smoothly without engaging the assisted braking mode. Each time this would lock up meant activating the substantial dynamic stretch and a very bouncy moment before disengaging the brake. It is also quite demanding on the biceps holding the device open. Using the low friction mode is quite smooth and the ropes slide well.
A problem arises when selecting a diameter of prusik cord to serve as a personal backup. One partner had a hard time gripping the rope with 7mm nylon static cord. The conventional guideline of 75% rope diameter or a 2mm differential means one would have to use a 5mm prusik with a breaking strength around 6kN which is not ideal. I did, however, find the Sterling Hollow Block gripped the ropes extremely well, owing to its hollow nature allowing for greater surface area contact.
|UIAA Fall Rating||5-18|
The Edelrid Skimmer Pro Dry 7.1 mm is exactly what gram-counters have been waiting for. A fully certified double rope allowing for half-rope technique on complicated routes without paying a weight penalty. Experienced alpine climbers could climb as a three person rope team, following on a single strand. The Skimmer is a near perfect rope for lightweight alpinism. Super light, doubly certified and UIAA Dry rated.
But with the weight savings comes an inevitable durability tradeoff. A cord as thin as 7.1mm means that the slightest strike of a crampon, nick on a rock or icefall could seriously compromise the integrity of the ropes. These are a specialist tool to be reserved for specialist applications. I would limit these to ice and alpine routes only and limit their rock exposure. Consider a different pair for the wandering traverses of Yamnuska. Inevitably, someone will ask about their suitability for glacier travel and ski mountaineering but I'll leave that opinion for an ACMG Ski Guide.
I've long been a fan of Edelrid ropes. Being the inventor's of the modern kern-mantle rope and building high quality climbing products for 154 years has established tenure and inspires confidence in the use of Edelrid technical products.At $529 CAN for the pair of ropes and one Micro Jul device, they aren't cheap. But for a specialist application, the weight savings will justify the cost.
As these ropes have not been adequately battle tested, I'm curious to hear what others have felt about them. If you've had a chance to climb on the Edelrid Skimmers let me know your thoughts in the comments below.
Note: Although Edelrid supplied me with these ropes for testing it in no way influences my opinions.