Thoughts on balancing "sewing it up" with rope drag.

It´s easier to measure than guess and possibly look stupid  

Case in point: if I had guessed I would have guessed that the drag would be reduced by a lot more than 8%.

What about for a bend less than 180° . Realistically, you aren't going to have a 180°  bend unless it's the top piece, so that isn't relavent. The worst you will get for a lower piece, which is what we're actually concerned about, is 90°.

C'mon, Jim, you usually post really good stuff, but right now your providing data for a situation that isn't relavent. Yes, the revolver isn't going to do you a whole lot of good used as a pulley for self-rescue, but that's not what we're talking about.

My personal experience climbing a zig-zagging crack is that the revolver cuts down on drag a whole lot more than 8%. Probably more along the lines of 20% 

Edit: Sorry, Jim, I failed to realize you were responding to a question about the revolver's performance as the top piece. My bad. However, I still want to make it clear that doesn't necessarily say anything about a revolver's ability to mitigate rope drag from a lower piece within the system.

eli poss wrote:

What about for a bend less than 180° . Realistically, you aren't going to have a 180°  bend unless it's the top piece, so that isn't relavent. The worst you will get for a lower piece, which is what we're actually concerned about, is 90°.

C'mon, Jim, you usually post really good stuff, but right now your providing data for a situation that isn't relavent. Yes, the revolver isn't going to do you a whole lot of good used as a pulley for self-rescue, but that's not what we're talking about.

My personal experience climbing a zig-zagging crack is that the revolver cuts down on drag a whole lot more than 8%. Probably more along the lines of 20% 

He was responding to a question about falling on a revolver.

I.e. fully loaded w/ 180 degree bend. 

nathanael wrote:

On the other hand one of my partners never leaves the ground without a triple rack and I hate carrying all that weight and bulk on lead. always a tradeoff.

Just because your partner wants to rack it doesn't mean you have to carry it all on lead. When you're getting ready to lead your pitch, take the gear you want and leave the rest with your partner. 

Likewise if your partner leads the first pitch, if they haven't racked something you'll want for your lead, take it with you. This is why I almost always follow pitches with tricams on my harness. Luckily they're light. ;)

Em Cos wrote:

Just because your partner wants to rack it doesn't mean you have to carry it all on lead. When you're getting ready to lead your pitch, take the gear you want and leave the rest with your partner. 

Likewise if your partner leads the first pitch, if they haven't racked something you'll want for your lead, take it with you. This is why I almost always follow pitches with tricams on my harness. Luckily they're light. ;)

Yea I started doing that so it's not that bad. At first I felt pressured to rack up with the whole thing when we switched leads.

eli poss wrote:

What about for a bend less than 180° . Realistically, you aren't going to have a 180°  bend unless it's the top piece, so that isn't relavent. The worst you will get for a lower piece, which is what we're actually concerned about, is 90°.

C'mon, Jim, you usually post really good stuff, but right now your providing data for a situation that isn't relavent. Yes, the revolver isn't going to do you a whole lot of good used as a pulley for self-rescue, but that's not what we're talking about.

My personal experience climbing a zig-zagging crack is that the revolver cuts down on drag a whole lot more than 8%. Probably more along the lines of 20% 

Edit: Sorry, Jim, I failed to realize you were responding to a question about the revolver's performance as the top piece. My bad. However, I still want to make it clear that doesn't necessarily say anything about a revolver's ability to mitigate rope drag from a lower piece within the system.

Reading before posting is also a good idea  .

I´m assured by my friends at DMM that the reduction in drag when used in a wandering line is considerable and took their word for it, I only tested it´s efficiency for rescue hauling as that was what was being discussed at that time for inclusion in a book. I could try to measure the effect in drag reduction but the actual forces are a bit on the low side for most of my load cells.

Em Cos wrote:

Likewise if your partner leads the first pitch, if they haven't racked something you'll want for your lead, take it with you. This is why I almost always follow pitches with tricams on my harness. Luckily they're light. ;)

I resemble that remark!

Jim Titt wrote:

Reading before posting is also a good idea  .

I´m assured by my friends at DMM that the reduction in drag when used in a wandering line is considerable and took their word for it, I only tested it´s efficiency for rescue hauling as that was what was being discussed at that time for inclusion in a book. I could try to measure the effect in drag reduction but the actual forces are a bit on the low side for most of my load cells.

I did read, but i forgot by the time I had read all the posts and decided to write a reply. My bad.

If you're ever bored at work (like most MPers) I would be interested to see how much the revolver reduces drag at a 90 degree angles which would represent a straight up crack and then traverse to the belay and the worst angle one could have for drag.

If you have the time, a 60 degree and 30 degree test would also provide data for more common situations.

David Kerkeslager wrote:

After some thought, I think this is what I needed to hear from this thread. I guess I've just got to suck it up and downclimb to backclean more often.

This!

But 1st time up, one is often not sure, eg, I had bad rope drag the first time I lead MF because I was reluctant to extend the pro before the traverse.  Much smarter second time around.  

Sometimes rope drag is bad at the Gunks because of the wandering and traversing nature of some routes.  While it is tempting to skip placing a piece after a testy traverse, do not forget to protect the second!  Or an epic may ensue.

S. Neoh wrote:

This!

But 1st time up, one is often not sure, eg, I had bad rope drag the first time I lead MF because I was reluctant to extend the pro before the traverse.  Much smarter second time around.  

Sometimes rope drag is bad at the Gunks because of the wandering and traversing nature of some routes.  While it is tempting to skip placing a piece after a testy traverse, do not forget to protect the second!  Or an epic may ensue.

Yeah, after a few scary traverses as a follow I always protect my follow well.

It's particularly scary following someone who's a better climber than you, and impatient. Maybe this traverse is easy for them, but not for you, and they're dragging you off balance with a tight belay the whole while!

You can quite easily sew up climbs and still have minimal rope drag.  VERY liberal use of alpine draws should leave your rope running in a straight path on all but the most zig-zaggy routes.  That said some climbs might go around and no matter what you do you cannot avoid the rope drag.

I've had 200foot pitches with 20 or so pieces of gear and still minimal rope drag.  Alpine draws and sometimes even double alpine draws if needed.  Keep your rope running straight and friction will be minimal.

Alright. I'm confused regarding the "180 deg bend". 360 is the full circle, which is the same as 0 deg, right? 180 is the straight rope with no bend at all, as far as I know.

Trying to understand the "180 deg bend" by itself, outside of the context of this thread, I picture the revolver on a sling mid-way through the chain, with the sling pulled horizontal by the rope running straight through. However, in the context of this thread, it seems that Jim and subsequent posters mean the angle the rope makes on the top biner after a lead fall (or top-rope catch) on a perfectly vertical route.

Please clarify.

jktinst wrote:

Alright. I'm confused regarding the "180 deg bend". 360 is the full circle, which is the same as 0 deg, right? 180 is the straight rope with no bend at all, as far as I know.

Trying to understand the "180 deg bend" by itself, outside of the context of this thread, I picture the revolver on a sling mid-way through the chain, with the sling pulled horizontal by the rope running straight through. However, in the context of this thread, it seems that Jim and subsequent posters mean the angle the rope makes on the top biner after a lead fall (or top-rope catch) on a perfectly vertical route.

Please clarify.

"No bend" is 0 degrees. 180 is a U turn.

jktinst wrote:

Alright. I'm confused regarding the "180 deg bend". 360 is the full circle, which is the same as 0 deg, right? 180 is the straight rope with no bend at all, as far as I know.

Trying to understand the "180 deg bend" by itself, outside of the context of this thread, I picture the revolver on a sling mid-way through the chain, with the sling pulled horizontal by the rope running straight through. However, in the context of this thread, it seems that Jim and subsequent posters mean the angle the rope makes on the top biner after a lead fall (or top-rope catch) on a perfectly vertical route.

Please clarify.

Look, my geometry was about forty years ago, okay?

But, you are correct. 180 is a straight line across a circle.

However, in everyday use, 180 usually means 180 degree change, or, a u- turn.

If you manage a full 360 while in the air, you will end up back at zero. But that change... WAHOOOO!!

Best, OLH

Jim Titt wrote:

While the Revolver does reduce the rope drag due to the low loads and smallish angles conerned as a top piece with 180° bend the actual reduction in friction is quite low, I´ve measured it against a standard 10mm polished pin for use in a hauling situation and see 8% less, (about the same as you used a 12mm round stock karabiner)

Not wanting to believe Jim's findings, I just did my own little test. I put a well-used 10.? mm rope at a 180 degree bend and measured the force need to lift a 26 lb car tire. With 12mm round stock biner: 52 lb (double the weight of the tire, yikes!). With a Revolver: 49 lb. About a 6% reduction Pfft!

Of course, a 180 deg change of direction is a U-turn. I guess the confusion comes from the word "bend" which can mean both 1) the change of direction of the road, the car, etc; and also 2) the static angle between two axes (strands of rope, anchor arms, etc.). I guess that when seeing angles discussed in climbing,  I'm more used to the latter meaning. In any case, it would be useful to clearly state what is measured: 180 deg change of direction of the rope between before and after a lead fall, or 0 deg between the two strands when top-roping or hauling (no change of direction between "before" and "after" in the latter two).

jktinst wrote:

Alright. I'm confused regarding the "180 deg bend". 360 is the full circle, which is the same as 0 deg, right? 180 is the straight rope with no bend at all, as far as I know.

Trying to understand the "180 deg bend" by itself, outside of the context of this thread, I picture the revolver on a sling mid-way through the chain, with the sling pulled horizontal by the rope running straight through. However, in the context of this thread, it seems that Jim and subsequent posters mean the angle the rope makes on the top biner after a lead fall (or top-rope catch) on a perfectly vertical route.

Please clarify.

"Bend;.to force (an object, especially a long or thin one) from a straight form into a curved or angular one". As we are "bending" the rope from straight  the angle we bend starts at 0° and a 180° bend is a U, Every bender I seen in 45 years of engineering is graduated this way and in common usage a 90° bend in the road is a right angle to the direction are travelling

jktinst wrote:

Of course, a 180 deg change of direction is a U-turn. I guess the confusion comes from the word "bend" which can mean both 1) the change of direction of the road, the car, etc; and also 2) the static angle between two axes (strands of rope, anchor arms, etc.). I guess that when seeing angles discussed in climbing,  I'm more used to the latter meaning. In any case, it would be useful to clearly state what is measured: 180 deg change of direction of the rope between before and after a lead fall, or 0 deg between the two strands when top-roping or hauling (no change of direction between "before" and "after" in the latter two).

Not only that, in common usage, 180, is the one that gets used this way, as far as I can tell. Everything else, the meaning stays about the same.

Good point, though!

Best, Helen

Gunkiemike wrote:

Not wanting to believe Jim's findings, I just did my own little test. I put a well-used 10.? mm rope at a 180 degree bend and measured the force need to lift a 26 lb car tire. With 12mm round stock biner: 52 lb (double the weight of the tire, yikes!). With a Revolver: 49 lb. About a 6% reduction Pfft!

Having moved this weeks project to the side  ( a rotary bioreactor) I can get to my winch again so I´ll run some numbers out in the next few days, we have two religous holidays on Tuesday and Wednesday   As you noticed, Revolver karabiners aren´t the most efficient pulleys in world.