Monday, August 16, 2010

The Skinny on Skinny Ropes

Typical Rope Mismanagement
Anyone who has bought a few ropes over the years has noticed a couple trends in regards to ropes. They're getting longer, stronger, and they're getting skinnier. For the new generation of climbers raised on sport climbing and gyms the oft heard lament of the old time climber, "I remember when ropes were only 50M and 11mm thick and we did just fine", seems like just another "back in my day" platitude. So is there a reason that ropes are getting longer and skinnier or is it just rope manufacturers way of getting us to shell out our hard earned cash for the latest and greatest?

First a little history on the rope manufacturing process and some info on modern rope construction. Before we had nylon ropes we had manilla or hemp. Generally these came in 120 foot lengths and were tied around the waist as modern harnesses did not exist. During this period the mentality that "the leader must not fall" was more about self preservation than style. Ropes could rot on the inside and break with very little force. Obviously we've come a long ways since then. Shortly after WWII nylon started to be used for ropes and while tied webbing harnesses were more commonly in use the level of safety increased drastically with the production of Goldline, a twisted nylon rope. Twisted ropes differ from braided ropes in that fibers of material are twisted into yarns which are twisted around each other in the opposite direction to get strands, which are again twisted around each other to get the final rope. While these ropes were a step forward, being stronger and lighter they were still not on par with what modern climbers are used to. Goldline and other rope brands were extremely stretchy and while most of them were around 120 feet in length and about 9-11mm in thickness there were some with the, then controversial, 150 foot lengths. These ropes had terrible handling characteristics as they were very stiff and twisted easily. This twist would try to come undone when the rope was weighted, thereby spinning the climber around.

Typical Rope Deconstructed
During this time braided nylon ropes were starting to also be manufactured but twisted ropes such as Goldline were common amongst climbers until the 1970's when kernmantle ropes that we are more familiar with became more commonly available. A kernmantle rope basically has two parts. The innner part, the kern, is composed of twisted strands of nylon. This is more commonly known as the core which is tightly wrapped in the braided nylon sheath, known as the mantel, thus kernmantle rope. Most of the strength of a rope (around 75%) is in the core as well as it's ability to hold multiple falls softly. The handling characteristics, such as how it feels in your hand or it's abrasion characteristics, are determined by the construction of the sheath.

It was also around this time that climbing ropes started to be measured metricly and 50M ropes became more common. In the 1972 Chouinard Catalog (Chouinard later became Black Diamond) the Fantasia rope came in 120, 150, and 165 foot (50M) lengths and was 11mm in diameter. There was also a 9mm version that could be used as a double rope set but was said to be capable of serving many mountaineering applications as a single rope. It's interesting to note that although a 50M version was offered the manufacturer discouraged people from purchasing it because it was heavier, costlier, and more difficult to coil. It was several years before this during which the UIAA began putting their mark on gear that met the standards they set forth for mountaineering and climbing equipment. The test for ropes to handle a Factor 2 Fall (a fall twice the distance of the length of rope between the belayer and climber) is still essentially the same. A 176 lb. weight is dropped 16.5 feet on a 8.25 foot section of rope.

Since kernmantle ropes construction became common the manufacturing process has evolved to make ropes longer, stronger, and skinnier. While 60M ropes became quite common in the 90's. Today 70M ropes are fairly common with 80M becoming the new kid on the block. 50M ropes are fairly uncommon these days. Today's single ropes are commonly less than 10mm with some almost breaking the 9mm barrier. Some twin ropes are as thin as 7.5mm. So then the question is, should you get a longer, skinnier rope? Of course the answer depends on what kind of climbing you do. It would be silly for someone doing big walls, with their constant abrading of the rope through climbing, ascending, hauling, and other common tasks, to get a 9mm rope which will be trashed after one climb. It's almost equally silly for someone wanting to redpoint their hardest climb ever to carry all the weight of an 11mm cord. They'd have a harder time finding a rope that thick anyways. For simple comparison though we'll assume an average all around climber who does a few weekend trips a month to sport climb, trad climb, or toprope, and occasionally does a mountaineering trip or climbs a big wall.

So what's the tradeoff in weight between a thick 10.7mm rope and a skinny 9.2mm rope of the same length. Well Sterling Rope Company offers their Ultra in 60M, 70M and 80M lengths. At 70 grams/meter that comes out to 9.3 lbs., 10.8 lbs., and 12.3 lbs. respectively. Their Nano on the other hand is only 52 grams/meter which comes out to 6.9 lbs., 8.1 lbs., and 9.2 lbs. respectively. So with an 80M Nano that's an additional 65 feet of rope and 1/10th of a pound less hanging of your harness or being lugged around in your pack. The Nano is rated to hold 6 UIAA falls (the test I mentioned with the 176 lb. weight) while the Ultra is rated for 8, just a few more. So while you save some weight and gain some added length. You may not save any money with the 80M Nano coming in at $269.00 from Sterling themselves. The comparably weighted 60M Ultra only costs $240.25. and will likely last a while longer under normal use.So with thicker ropes you have more weight but also generally more resistance to abrasion. So these are going to take a beating and still catch you in that 50 foot screamer. If you do a lot of toproping, big wall climbing, or operate a climbing gym or guide service single ropes bigger than 10mm are the way to go. If on the other hand you climb fairly infrequently and do a lot more alpine climbing, redpoint attempts or don't fall frequently then single ropes in the 9mm range may be more to your liking. 
The Guts of A Rope
Most of us don't specialize though so what's the best rope for someone who does a little bit of everything? While a 60M rope still gets you up most anything a 70M is helpful when you go to climbing areas that may not have that standard 60M length or if you want to link pitches on multipitch routes. With skinny ropes being fairly durable as compared to thicker ropes the question really depends on how often you want to buy a new rope.Thicker ropes tend to have thicker sheaths and will stand up to much more abuse than a skinnier rope. So if the type of climbing you do involves a lot of rope abrasion, you climb a lot more than your average climber, or you are clumsy and tend to drag your rope through the dirt then it might be best to get a little bit thicker rope. If you baby your rope and are a more recreational climber who doesn't do any big wall climbing then a skinny rope will probably suit your needs just fine. Below is a comparison chart that shows the different weights, costs, and UIAA falls caught, of several different rope manufacturers.

Sterling Pro
10.1mm63g/M6 Falls
$274.65 (70M DRY)
Mammut Galaxy10mm66g/M7 Falls
$249.95 (70M DRY)
Beal Flyer II10.2mm64g/M11 Falls
$249.95 (70M DRY)
Edelweiss Onsight9.9mm64g/M8 Falls$259.95 (70M DRY)
Maxim Glider9.9mm63g/M7 Falls$196.00 (70M DRY)

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