Rope Width Vs Weight

I was just doing some reading over at outdoorgearlab on their rope recommendations. I noticed that the lightest rope they tested was the 8.9 mm Metolius tendon which weighs in at 52g/meter whereas the heaviest ropes tested were the Maxim Glider and Equinox at 66g/meter.

Now obviously the thinner rope is lighter, but how much so?

Let's do some basic math:

The standard rope is length is 60 meters in most places
Light rope: (60 meters)*(52g/meter)=3120 grams=3.12 Kg
1Kg=2.2 lbs
3.12kg*2.2lb/Kg=6.9 lbs
So if you were to climb a full pitch you'll be carrying an extra 7 lbs just in rope

Let's check out the heavy hitters:
66g/m*60m=3960 g= 3.96kg
3.96Kg*2.2lbs/kg=8.7 lbs

8.7-6.9=1.8 lbs

If I'm not being a dumbass per usual, there is only a 1.8 lb difference over the course of 60 meters between an 10.2 mm diameter workhorse of a rope and an 8.9 mm thin rope that will be worn out relatively quickly.

Is a 1.8 lb difference worth so much to everyone? Just leave your cordellette and #3 on the ground and you've more than made up the difference in weight.

Not that it's worth much, but the 8.9 is rated for 5 UIAA falls. The maxims are rated to 9.

If my calculations are right, what is the obsession with skinny ropes these days?

1.9 lbs is quite a bit. Most climbers would be more than happy to ditch that much weight. Also I believe that the advertised diameter only needs to be within 0.5 mm of the measured diameter. So a 9.5 mm rope could be sold as 10 mm or 9 mm.

1.8 lbs savings on the rope = 1.8 lbs of food/water I can hike in into the backcountry. On full rope pitches, those 10 gram/meter will be quite noticable. Oh, and since I don't feel as comfortable on overhanging cupped hands, I'll bring the #3, thank you.

Bill Wa wrote:You obviously don't lead trad. Clipping skinny ropes is much easier.

Yes, clipping the rope is what makes climbing trad hard...

This is actually a keen observation, and I definitely spent a long time in the "what's the big deal?" camp. I have multiple 9.8s that I use as work horses still. for falling all over sport routes at your home crag, etc., I wholeheartedly agree that thicker ropes still have some real advantages.

As the other posters have said, the ~2lbs is an appreciable amount, but you must also consider how much more surface area a thicker ropes has to drag through your carabiners. What is mildly annoying rope drag with an 8.9mm rope might be absolutely heinous with a 10.2. Essentially drag will act as a scaling factor in rough proportion to the rope-to-biner contact area. So though they might be less than 2 pounds difference when straight up and down, the real-world difference can be much greater than that when drag through a wandering pitch (or over a bulge) is taken into account.

Thinner ropes also stretch more and tend to give softer catches. This fact alone is really more of bonus compared to the reduced weight/drag, but it can still be nice.

Bill Wa wrote:You obviously don't lead trad. Clipping skinny ropes is much easier. That #3 you talking about leaving on the ground or that cordelette could be the critical pieces you will need to complete your pitch. Get outside. Get on some trads. Then you will know what the hype is all about. And yes 1.9 lbs IS a lot! Question answered. End of conversation.

You can lead in the gunks for years without ever picking up a #3...
I can anchor just fine with the rope...

you were saying?

Dave Alie wrote:This is actually a keen observation, and I definitely spent a long time in the "what's the big deal?" camp. I have multiple 9.8s that I use as work horses still. for falling all over sport routes at your home crag, etc., I wholeheartedly agree that thicker ropes still have some real advantages. As the other posters have said, the ~2lbs is an appreciable amount, but you must also consider how much more surface area a thicker ropes has to drag through your carabiners. What is mildly annoying rope drag with an 8.9mm rope might be absolutely heinous with a 10.2. Essentially drag will act as a scaling factor in rough proportion to the rope-to-biner contact area. So though they might be less than 2 pounds difference when straight up and down, the real-world difference can be much greater than that when drag through a wandering pitch (or over a bulge) is taken into account. Thinner ropes also stretch more and tend to give softer catches. This fact alone is really more of bonus compared to the reduced weight/drag, but it can still be nice.

The rope drag is actually a really good point. I climb on either a 9.8 or 8.6 half ropes and I find the half ropes can end up with more drag if you misjudge the pitch. They're also heavier than a single anyway, but they also have an inherently softer catch

1. as noted thicker ropes had a bit more drag, this is especially true if you are using these new micro biners

2. the variability of the rope diameter used to be +/- 0.3mm ... this has changed very recently to +/- 0.2mm ... which means that 9.8mm rope could be 9.6mm or 10mm ... look at rope weight rather than diameter

3. there is no real correlation between diameter and the impact force of the rope ...

take the mammut 8.7mm serenity with an impact force of 8.4 KN ... compare this to the mammut supersafe EVO 10.2mm at 7.7 KN ...

and we wont even talk between different brands ... the beal top gun 10.5mm is rated at 7.4 KN

mammut.ch/en/productDetail/…

mammut.ch/en/productDetail/…

bealplanet.com/sport/anglai…

4. however a thinner rope may allows more slippage in certain devices ... giving a more "dynamic" belay ....

from Jim Titt's page

bolt-products.com/Glue-inBo…

5. as to why people use em ... for some things like alpinism, long multi with long approaches, very hard sport redpoints, etc ... the weight savings, ease of clipping and lower drag can be significant

my opinion is that i save thinner (and half) ropes for when its really beneficial ... 90% of the time i climb on a good 9.8mm-10.3mm single ....

i can buy em cheap, abuse em, climb close to my limit (yes even on trad) with em, etc ...

they last longer, and i replace em for about 100$ a pop ... that way i dont need to worry about wrecking my $$$$ ultra thin dry treated spaghetti line for more general use

unless yr a total badass i dont think the rope diameter is whats limiting you

;)

Great response Bear!

Thanks for the detail

Bill Wa wrote: Leading in the Gunks you don't need a lot of stuff. It does not mean everybody is only leading in the Gunks. Broaden your horizons. There is so much more out there....like the whole Mid West. Leading at the Gunks will seem like climbing a frozen silo all winter and calling yourself an ice climber. Do we also have to get into the long discussion about PAS vs rope vs cordelette anchoring? Go West! End of topic.

Not looking to ruffle any feathers are we Billenor?

Even without the rope drag, on longer mega pitches 120' and up (steep sport or desert splitters) pulling the weight of the rope to clip could be a bitch. Fat ropes are for working and skinny ropes are for sending.

"Leave behind the #3 and the cordelette" -- I take it you don't do much alpine / backcountry climbing? The rack is already pared down at that point. If I thought I could leave any piece of gear behind without seriously jeopardizing my safety, I would. If it's a moderate climb (for me) I usually DO leave the #3 behind and just bring a big hex or two.

The fall rating really doesn't matter as much, since if you're taking repeated whippers in the alpine you probably have more pressing issues than rope wear.

That being said, I use a 9.8 for basically everything other than the above scenario, and yes I think it's silly when I see people TRing on an 8.7 at JTree.

doligo wrote:Even without the rope drag, on longer mega pitches 120' and up (steep sport or desert splitters) pulling the weight of the rope to clip could be a bitch. Fat ropes are for working and skinny ropes are for sending.

Over 120 feet the difference in weight barring rope drag is only 1 lb. I'd be impressed if anyone is sensitive enough to really notice that weight in a test-retest situation. There's no evidence behind that, but it would make for an interesting test.

Ryan Watts wrote:"Leave behind the #3 and the cordelette" -- I take it you don't do much alpine / backcountry climbing? The rack is already pared down at that point. If I thought I could leave any piece of gear behind without seriously jeopardizing my safety, I would. If it's a moderate climb (for me) I usually DO leave the #3 behind and just bring a big hex or two.

Why in the world would you do that?

#3 Camalot
201g/14kN

#11 Hexentric
206g/10kN

Mark Paulson wrote: Why in the world would you do that? #3 Camalot 201g/14kN #11 Hexentric 206g/10kN

Kind of beside the point but since you asked...

The hexes I have are lighter than the BD ones by a bit (dmm). And full disclosure, if I just needed 1 number 3, I'd just bring it. I was thinking more of a situation where you want doubles of larger cams (say petit grepon it's nice to have extra #1-2). In that case I might bring a single set of cams, plus a few hexes/tricams whatever.

Minor weight savings, plus if you have to bail, I'd much rather leave a hex.

Also RMNP seems to have some of those weird placements where a cam is dicey but a hex is bomber.

Didn't realize how heavy the bd hexes were though. Good point.

Ryan Watts wrote: Kind of beside the point but since you asked... The hexes I have are lighter than the BD ones by a bit (dmm). And full disclosure, if I just needed 1 number 3, I'd just bring it. I was thinking more of a situation where you want doubles of larger cams (say petit grepon it's nice to have extra #1-2). In that case I might bring a single set of cams, plus a few hexes/tricams whatever. Minor weight savings, plus if you have to bail, I'd much rather leave a hex. Also RMNP seems to have some of those weird placements where a cam is dicey but a hex is bomber. Didn't realize how heavy the bd hexes were though. Good point.

I own a single hex ... The blue dmm torque nut

It weights 146g, is the same colour as the #3 camalot, and has a long extendible sling so its also a runner (useful for slinging horns where you want to weight the placement a bit)

It works in wet, muddy, icy cracks

But most importantly if i need to leave it behind i aint crying

Personally i think the DMM hexes are the way to go as you get an extendible sling even if you dont place the hex

;)

John Wilder wrote: The problem with that idea is that rope drag is always a factor (except in the desert, but thats a small chunk of the climbing population- most of us dont climb perfectly straight pitches). I much prefer skinny lines- and since they last as long as the fat ones (roughly 1.5 to 2 years for me), i'm happy to pay the premium for them. I like the lighter weight, less drag, and easier clipping. It's worth it for me personally.

I agree with all this, and for these reasons prefer skinny ropes. Another benefit not mentioned yet--but probably the biggest deal for me--is that skinny ropes handle better for belaying, knots, and anchor building. In particular, cloves hitches are much smaller and tidier with a skinny rope, especially in a small wiregate, than they are with a stiff, fat 10.2. This makes building the anchor with the rope much easier and tidier. The skinny ropes also feed much more nicely through a belay device, especially when belaying the second off of an autoblock (skinny rope makes my elbows much happier in this scenario, or when belaying the leader with a Gri Gri (even a Gri-Gri 1; trying to get a fuzzy 10.2 through one of those is heinous).

The big question for me isn't whether a skinny rope (say, sub-9.8 mm) is better (it unquestionably is, in my mind), but how skinny to go. For me, it depends on the situation. For general purpose sport and trad cragging, 9.6-9.8 is my favorite. Any skinnier and you lose some durability, plus it is hard to boink with; any thinker and using a Gri Gri or Reverso gets annoying. For a long trad route with a bit of an approach, something thinner/lighter can be nice, like in the 9.2-9.4 range. Less weight on the hike, less rope drag, easier handling, etc, but still thick enough to be happy falling on. For an long easy route (falling unlikely) with a long appproach, it can be nice to go ultra-skinny, like sub 9mm. For these sorts of routes (like climbing the Exum Ridge, etc.), my rope of choice is to use one 8.5 mm half rope by itself.

The obsession with skinny ropes is the same obsession displayed by spandex wearing road bikers. An obsession with an illusion. Get all the lightweight gear the pros are using and attain a higher number. But why? Numbers don't coorelate to enjoyment or effort. Numbers support the illusion.

Sure there are times when there is a practical benefit to lightweight stuff, really long approaches and such. But 99% of the time for 99% of climbers it's only an idea. An idea that depends on consumer culture to buy into it, literally.

MC Poopypants wrote:The obsession with skinny ropes is the same obsession displayed by spandex wearing road bikers. An obsession with an illusion. Get all the lightweight gear the pros are using and attain a higher number. But why? Numbers don't coorelate to enjoyment or effort. Numbers support the illusion. Sure there are times when there is a practical benefit to lightweight stuff, really long approaches and such. But 99% of the time for 99% of climbers it's only an idea. An idea that depends on consumer culture to buy into it, literally.

Could also be that there are people who make enough money that the extra $50 or $100 or whatever for a skinny rope doesn't really matter.

If you're behind on rent to support your gear habit, that's one thing.

But if its discretionary income, spent on gear for an activity you enjoy, why not?

Call it consumer culture if you want I guess.

It's nice to have a skinnier rope just for something that is smaller on approaches. Takes up less space in the pack.

As to ease of feeding and knots

While its VERY generally true that skinnier ropes feed better and are a bit more supple ... This depends on the particular rope itself

I have 10.2mm tendon ropes that feed much better than even 9.5mm mammut in grigris and smarts

There are plenty of 10mm (tendon, beal, edelrid python) ropes that will handle smoother and better than many "stiff" thinner ropes (maxim,mammut)

The thing to remember about 9.8-10.3mm ropes is that this is the sweet spot of value

You almost always find em on sale around 100-120$ ... They generally last a decent amount of time

And when you retire them from leading, theyll last a good amount of time for TR and fixed lines

Most "thin" (57 gm and less) ropes often run you around 200$

And the dry coating will wear off in around 100 pitches if yr using them for alpine/ice ... So if you use em for general cragging, short multi it may defeat the purpose

;)