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Skinny Rope Review – No 224 – September 2003

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Slinging a skinny, lightweight cord can make the difference between redpoint success and ego-crushing failure.

Skinny Rope Review - No 224 - September 2003

Get the skinny on the latest narrow- diameter single ropes

Up until the late 1980s, your choice for rope diameter was simple and singular: 11 millimeters. When 10.5mm cords debuted around the time Reagan left office, there was much consternation among the skeptics, who questioned the safety and durability of such a “skinny” cord. However, most climbers quickly jumped onto those leaner lines, and, by Clinton’s second term, virtually every manufacturer had a 9.8mm on the market. Now, during the madness of King George, 9.5mm is in vogue, 9.3mm is fresh on the market, and at least one 9mm single lead line will debut within the next year.

Within the narrow-diameter rope market, you have a wide variety of options. Many of today’s 9.8mm cords are full service — you can use them for practically any facet of climbing except heavy-duty wall climbing, which dishes out serious wear and tear to even the stoutest 11mm ropes. However, the skinnier you get, the more your options narrow, as durability becomes a significant issue. Ropes 9.5mm and under should be reserved for sport-climbing redpoints, alpine climbs where double ropes aren’t required, and steep multi-pitch free routes where rock abrasion is not an issue.

If you decide to purchase a skinny cord, it is important to run it through your

belay devices

to make sure it locks off properly. Tube-style devices designed to handle both single and double ropes should have no problem. However, Petzl says that the Grigri, their ubiquitous sport-climbing autolocker belay device, will only handle ropes as thin as 9.7mm. Also, until the rope softens a bit and the dry coating roughens up, always tie in with a figure-8. Double bowlines have been known to unravel with stiff, skinny cords.

Our nine test ropes ranged from a burly 9.8mm to a svelte 9.3mm, all dry-treated. Our primary areas of subjective testing were clipping (directly affected by a rope’s stiffness), belaying (affected by stiffness and the sheath’s feel), and rope drag. When making your purchase, factor in our first-person experiences, but also consider certain certification data on the informational hangtag in the rope package. Each rope in our collection has been tested in a Union Internationale des Associations d’Alpinisme (UIAA)-certified facility according to standards set by the UIAA and the Euro Norms (EN) group.

Of those standards, the following are the most important:


If you cut off a one-meter section of your rope and weigh it, it will weigh more than the manufacturer’s grams-per-meter hangtag number. Rather than simply slicing off a hunk of cord, the UIAA makes their measurement by weighting a section of rope with 22 pounds, cutting one meter from that stretched section, and then weighing it.


Why is it that two ropes from different manufacturers with the same diameters listed on their respective hangtags seem to have different thicknesses? As with weight, the UIAA determines diameter by weighting a section of rope and taking several measurements, which are then averaged to produce the final diameter.

Falls held.

The UIAA standard fall test is thankfully very severe, far outstripping almost any fall you might encounter in the real world. For the test, a 175-pound weight is dropped 15 feet on a nine-foot section of rope over a 10mm radius (to simulate a


catching the rope), resulting in a wrenching 1.78-factor fall. Every single rope must hold five of those falls to be certified; each rope in our test is certified to have survived at least six. There is also an optional UIAA “sharp-edge” test in which the 10mm radius is replaced with a 90-degree, .75mm edge. A rope must survive one fall to be certified. As some manufacturers are disputing the validity of this test, the UIAA Safety Committee has formed a working group to develop a more accurate test of a rope’s sharp-edge resistance.

Static and dynamic elongation.

Static elongation, the UIAA’s current required elongation measurement, is determined by weighting a section of rope — the lower the elongation, the less rope stretch when you’re dogging up a route. Dynamic elongation is measured on the first fall of the standard UIAA fall test. Simply put, it is a measure of how much stretch will occur during a 1.78 fall-factor drop — an extreme indicator of how much a rope will stretch during a normal fall. The higher the dynamic elongation percentage, the cushier your fall. However, the more your rope stretches, the farther you fall, a consideration in groundfall/ledgefall situations. The dynamic elongation test is not currently required for UIAA certification, though many manufacturers list it in their literature.

The test results

Beal Stinger

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