Mountain Project Logo

Maximum weight differential between belayer and climber on lead?

20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346
Emil Briggs wrote: Oh nonsense. Unless you're comparing the exact same fall under the exact same conditions with the two ropes your statement is meaningless. A lower impact force rope gives a softer catch. In this case it's about 22% softer. And that force reduction holds no matter what the length of the fall. In a 5 foot fall your soft catch can make a difference comparable to the lower impact rope. In a 20 footer the Beal is going to be a hell of a lot softer than your Maxim unless your belayer has a 40 inch vertical leap.
Were talking about two different things here. I am not talking about the effect a high-elongation rope has on limiting the impact force on the top piece. The term "soft catch" primarily refers to limiting the pendulum effect that occurs during a lead fall (although jumping does have a large effect on the load experienced by the top piece as well).

When a climber falls, s/he usually falls backwards to some effect, which is illustrated in just about any slow-mo video of a climber falling. As the climber passes his or her piece and the rope catches, if the belayer does not react appropriately the climber will accelerate toward the rock in an arc, which results in the climber slamming into the rock (i.e. hard catch). I have experienced this more times than I can possibly count, and this phenomenon is very well understood and known in the climbing community. There are about a million videos on YouTube you can watch that explain the effect. By stepping into the fall or jumping, the belayer greatly lessens the pendulum effect, thereby providing a "soft catch."

What I am saying is that simply purchasing a Beal rope will not eliminate the possibility of slamming your climber into the rock if you still continue to belay incorrectly. I can very easily give someone a hard catch with any rope on the market if I so wish, and I can provide a soft catch as well. Again, think pendulum, not impact force.

You are correct that as rope drag increases and the climber advances through a pitch, the belayer has less of an effect on providing a soft catch, but for most pitches under 100', the belayer has plenty of effect and especially so in the first eight bolts or so.
20 kN · · Unknown Hometown · Joined Feb 2009 · Points: 1,346
eli poss wrote:just out of curiosity, weighing 140, do I need to learn how to give a soft belay or am I light enough that it won't make a difference? FWIW, I mostly climb with people heavier.
Everyone should know how to provide a soft catch IMO, it's a part of belaying correctly. Eventually you will climb with someone the same weight as you, or lighter, and then you will need to know how to provide a soft catch. You should also know how to provide a hard catch and running belay as those will become necessary if you climb long enough. Eventually someone's going to blow a clip close to the deck, or someone is going to fall over a ledge, and you will need to know what to do in those situations. There are videos on YouTube that can get you started.
Emil Briggs · · Unknown Hometown · Joined Sep 2013 · Points: 125

I'm not sure what point you're trying to make here. If you had read my response to Chris you would have noticed I've already said that a "soft catch" can make a difference. What we're talking about is the size of the effect compared to that from using a lower impact rope. So lets look at some numbers

A world class athlete executing a perfectly timed jump might give you three feet. Most of us aren't world class athletes though and a more reasonable upper limit is probably 18 inches for fit young males and quite a bit less for females and older men. Instead of jumping one can of course step in to the fall. How much additional slack you get here depends on the distance to the first bolt/piece, the angle of the rope from vertical and how far you step. The greater the angle from vertical the more you will get. If the first bolt is at 15 feet and you are 5 feet back from the bolt then stepping in 2 feet will provide 6 inches of addtional slack. Make it 10 feet back and step in two feet and you'll get an extra 12 inches of slack.

Now just what does this extra slack do in the case of a fall? The force of gravity on a climber is always straight down. In order to convert the climbers vertical motion into horizontal motion you need to apply some horizontal force to the climber for a period of time. Extra slack will reduce the period of time the force is applied while a low impact rope will reduce the applied force. Obviously the relative magnitude of each effect depends on both how long the fall is and the mass of the climber (vertical acceleration is independent of mass but horizontal acceleration will be larger for a lighter climber). There are other factors as well such as friction and how tight the rope was at the point of the fall. But in a long enough fall the effect of jumping or stepping in is going to be much smaller than the effect of a low impact rope.

Note that additional slack can also be introduced in the system without jumping or stepping in. Being short roped is bad belaying practice and a good belayer typically leaves some slack in order to prevent this which is probably just as large as the distance that most people can jump.

20 kN wrote: Were talking about two different things here. I am not talking about the effect a high-elongation rope has on limiting the impact force on the top piece. The term "soft catch" primarily refers to limiting the pendulum effect that occurs during a lead fall (although jumping does have a large effect on the load experienced by the top piece as well). When a climber falls, s/he usually falls backwards to some effect, which is illustrated in just about any slow-mo video of a climber falling. As the climber passes his or her piece and the rope catches, if the belayer does not react appropriately the climber will accelerate toward the rock in an arc, which results in the climber slamming into the rock (i.e. hard catch). I have experienced this more times than I can possibly count, and this phenomenon is very well understood and known in the climbing community. There are about a million videos on YouTube you can watch that explain the effect. By stepping into the fall or jumping, the belayer greatly lessens the pendulum effect, thereby providing a "soft catch." What I am saying is that simply purchasing a Beal rope will not eliminate the possibility of slamming your climber into the rock if you still continue to belay incorrectly. I can very easily give someone a hard catch with any rope on the market if I so wish, and I can provide a soft catch as well. Again, think pendulum, not impact force. You are correct that as rope drag increases and the climber advances through a pitch, the belayer has less of an effect on providing a soft catch, but for most pitches under 100', the belayer has plenty of effect and especially so in the first eight bolts or so.
csproul · · Pittsboro...sort of, NC · Joined Dec 2009 · Points: 330

If I understand what you wrote, I think what you're ignoring is the magnitude of the vertical component in "stepping into" the fall. I'm not talking about stepping into a fall by adjusting how far you are belaying away from the wall and thus how far you move in a horizontal component. I'm talking about how much you allow the fall to pull you up vertically.

I was catching a climber a few weeks ago. He repeatedly took falls from the same place, somewhere around 20ft. (~8-10ft above the gear). In some instances, I stepped into the fall and was pulled up ~10ft. Not a 3 ft world class jump. I doubt my leaping ability is more than 10 inches! On another fall from the exact same place, I was not paying close attention, muffed up the catch and sat back on the rope as he fell. In this case I was not pulled up more than a foot or two. So we're now talking about a ~8ft difference in the vertical component of a fall ~10 ft above the last piece of gear. The difference in how the climber hit the wall was clear as day.

Now, how does that compare to the difference felt by the climber when using two ropes with different impact factors? I'll let you calculate that...that's above my skill/ambitions.

Emil Briggs · · Unknown Hometown · Joined Sep 2013 · Points: 125

I don't doubt you but it was not a controlled experiment. Stepping in as opposed to sitting back would have had some effect but so would the amount of slack in the system, friction depending on where the rope was running and even how many falls the climber took and how much time there was between them.

One thing I think is worth noting is that the original question in this post asked about the maximum weight differential between the belayer and the climber. But another important question would be what rope is appropriate for climbers of different sizes. Emma weighs a little more than 100 pounds and I have another partner who weighs 215. Fall characteristics are going to be quite different for them.

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065

Even a single pitch sport route may have enough drag that you barely feel the fall especially with a lighter climber

Heres a climb where my partner took a 20 foot whipper at the top .... I barely felt the catch, theres enough bends in the rope and friction on the rock, especially with short draws ... Basically it was mostly rope stretch .... In retrospect he should have downclimbed and unclipped the second draw and use longer draws (but hey its a sport route)

Trunk monkey 12a, chekeamus canyon, squamish

On multi you climber may well be anchored in or in a hanging belay and soft catches may not be possible unless u use the rope slip method (risky)

The point is while the soft catch is great it is not something that can be depended upon in many situations, especially outside of the steep single pitch straight line climb cragging context

And even then there are many sport climbs that wander or have significant friction points especially with the short draws commin in sport climbing

Not to mention yr belayer can stumble or otherwise screw up when providing a soft catch especially if the ground is rocky

There is also a very real risk or repeated higher impact falls (whether because of hard catches, or of harder catching ropes when u cant get a soft catch) causing whiplash or back pain over the years ... I know of at least one climber who has had back issues ...

For a big weight difference IMO a softer catching rope is better

- heavier climber belaying lighter climber .... Softer catching rope gives you a bit of insurance if the soft catch isnt perfect

- lighter climber anchored in (you will do this sooner or latter with a large weight difference or on multi) ... Even with a bit of loose slack in the rope tether, the softer catching rope again gives you a bit of insurance and reduces the fall forces on trad ... It also reduces a bit the force felt bu the belayer

;)

csproul · · Pittsboro...sort of, NC · Joined Dec 2009 · Points: 330
Emil Briggs wrote:I don't doubt you but it was not a controlled experiment. Stepping in as opposed to sitting back would have had some effect but so would the amount of slack in the system, friction depending on where the rope was running and even how many falls the climber took and how much time there was between them. One thing I think is worth noting is that the original question in this post asked about the maximum weight differential between the belayer and the climber. But another important question would be what rope is appropriate for climbers of different sizes. Emma weighs a little more than 100 pounds and I have another partner who weighs 215. Fall characteristics are going to be quite different for them.
Totally agree with you Emil. Rope matters. The differential between the climber/belayer matters a lot, especially in the ease with which you can modulate the catch for "harder or softer".

The thing I'd like you to consider is that you and I are both basically of the same age and experience and largely come at climbing from the perspective of trad climbers who have done relatively little falling over our climbing lives. Compare that with climbers who now learn by sport climbing and take those skills into the trad world. I'm talking climbers/belayers who routinely take/catch dozens of falls every time they go out climbing, if not more. Watch and learn from them and you will find it is not that difficult to modulate the length of a fall by a significant amount, and that it makes a difference to the climber. I've really enjoyed climbing with people like this and I feel like I've learned a lot from them.

Now, if what I'm saying is true, consider who you want belay to belay you. All other factors being equal and both belayers have equal competence as far not dropping you, do you want 1) the crusty old climber with 30 years experience who sits like a bump on the ground and allows the rope to do all the work. Sure s/he's been climbing 30+ years, but in that time has caught maybe 100 falls. or 2) a climber who has caught 1000's of falls, is engaged while you are climbing, and has learned to catch you softly when appropriate and to give you a hard catch to keep you off the ledge below you when appropriate.

Of course this is kind of a false dichotomy for effect. The reality is often somewhere in between. I do find it funny to hear 200 lb people exclaim that a soft catch is a myth. They always get soft catch, and have to work harder to consciously give a softer catch. Conversely, people of our....stature...pretty much give softer catches by default (unless you're belaying Emma). I have to work to reduce the size of bigger falls when the climber significantly outweighs me. The other consideration, of course is the situation. I don't belay the same way when watching a climber from the ground with a clear line of sight as I do when I'm tied to an anchor, 150ft of rope out, and a climber out of sight...or worse yet, when belaying an aid pitch while my out of sight partner takes 2+ hours to finish a pitch!

end essay/
Bill Kirby · · Keene New York · Joined Jul 2012 · Points: 480

You guys keep talking about the traddies who don't know how to provide a safe catch and sport climbers that do. Don't forget everyone's favorite group who really have a bunch of lead fall experience.. Lead climbers at the gym.

bearbreeder · · Unknown Hometown · Joined Mar 2009 · Points: 3,065
Bill Kirby wrote: You guys keep talking about the traddies who don't know how to provide a safe catch and sport climbers that do. Don't forget everyone's favorite group who really have a bunch of lead fall experience.. Lead climbers at the gym.
those tend to be very low friction steeper falls in straight lines ...

in other words as "ideal" conditions as you can get for a soft catch

add some significant rubbing against the rock, a wandering path for the draws and a few features ... and the game can change ... not to mention sharp rocky ground that doesnt make it as easy to move around as a nice gym floor

as you can see even adding a slight bend increase the force ... but more important decreases the pull felt by the belayer ... as many a belayer depends on this to get "puled up" or "time" the soft catch, with more real world rock friction (the petzl tests were done in a steep wall in the gym) this may well prevent a soft catch

petzl test

the best place to practice catching whippers is the gym ... but a wise breeder of bears will recognize that it is an "ideal" scenario and on actual rock it may not be as applicable

gym bred beahs arent necessarily rock bred beahs

;)
Emil Briggs · · Unknown Hometown · Joined Sep 2013 · Points: 125

Good points. I completely trust you to belay me :) and a few others but yeah the situation matters. Emma is great and has caught me a bunch of times but if I were to try leading something like Captain Crunch at Stone again (probably ain't going to happen!) I wouldn't want her to belay me. Somebody like Bill or Jake who can do a running belay and is big enough not be knocked off their feet when the rope comes taught would be my choice. The practice point is valid but it has a corollary. Somebody like Jake is going to be bigger than most climbers so soft catch technique is not only more important for him he will also get more opportunity to practice it. For Emma the opposite holds. She rarely needs it or gets a chance to practice it.

csproul wrote: Totally agree with you Emil. Rope matters. The differential between climber/belayer matters a lot, especially in the ease with which you can modulate the catch for "harder or softer". The thing I'd like you to consider is that you and I are both basically of the same age and experience and largely come at climbing from the perspective of trad climbers who have done relatively little falling over our climbing lives. Compare that with climbers who now learn by sport climbing and take those skills into the trad world. I'm talking climbers/belayers who routinely take/catch dozens of falls every time they go out climbing, if not more. Watch and learn from them and you will find it is not that difficult to modulate the length of a fall by a significant amount, and that it makes a difference to the climber. I've really enjoyed climbing with people like this and I feel like I've learned a lot from them. Now, if what I'm saying is true, consider who you want belay to belay you. All other factors being equal and both belayers have equal competence as far not dropping you, do you want 1) the crusty old climber with 30 years experience who sits like a bump on the ground and allows the rope to do all the work. Sure s/he's been climbing 30+ years, but in that time has caught maybe 100 falls. or 2) a climber who has caught 1000's of falls, is engaged while you are climbing, and has learned to catch you softly when appropriate and to give you a hard catch to keep you off the ledge below you when appropriate. Of course this is kind of a false dichotomy for effect. The reality is often somewhere in between. I do find it funny to hear 200 lb people exclaim that a soft catch is a myth. They always get soft catch, and have to work harder to consciously give a softer catch. Conversely, people of our....stature...pretty much give softer catches by default (unless you're belaying Emma). I have to work to reduce the size of bigger falls when the climber significantly outweighs me. The other consideration, of course is the situation. I don't belay the same way when watching a climber from the ground with a clear line of sight as I do when I'm tied to an anchor, 150ft of rope out, and a climber out of sight...or worse yet, when belaying an aid pitch while my out of sight partner takes 2+ hours to finish a pitch! end essay/
FrankPS · · Atascadero, CA · Joined Nov 2009 · Points: 276

Zac (OP), did the responses answer your question? Was your question about soft catches?

csproul · · Pittsboro...sort of, NC · Joined Dec 2009 · Points: 330
Jake Jones wrote: I agree. There are a myriad of factors involved in how someone belays and they include but aren't limited to: What terrain you're on What type of route it is How much drag is in the system Line of sight Rope properties Weight of both belayer and climber My only aim with posting was to dispel the notion that many seem to adopt, that using the upward momentum of a belayer in appropriate scenarios doesn't make a difference with regard to impact force. It absolutely does.
This^^

And threads evolve. They may go off on tangents. It happens. Welcome to the internet. It doesn't make this discussion less valid. Sometimes good discussion happens that has nothing to do with the OP. Sometime off topic discussion is useless drivel. In this case, I think the thread has mostly been productive and should have helped answer the OP. Even if it is nothing most of haven't heard 100 times before.
FrankPS · · Atascadero, CA · Joined Nov 2009 · Points: 276
Jake Jones wrote: Hahaha Frank. Good man. However, I think csproul is right. As long as the tangent doesn't devolve into an outright pissing match, sometimes tangents can be very beneficial.
I was just curious because the OP hadn't weighed in since he started this four days ago.
Shelton Hatfield · · Unknown Hometown · Joined Apr 2011 · Points: 650
brandonemery wrote:First off, the catch on an X rated fall would be quite soft, as the ground would be doing 100% of the catching not the belayer, most the time that is. If you take an X rated fall it's very likely that you are going to die, and if you don't, you'll wish you did because you would probably break nearly every bone in your body. That's what X means, X signifies that there is a death fall on the route, just for clarification. falls aren't rated with "X" or "R", falls are rated on a scale based on the amount of rope that is out, and how far you fell. If you have placed zero protection and you climb 15 feet and fall, you will fall 30 feet, 30/15=2 which is a factor 2 fall. By definition a factor 2 fall is falling the whole length of rope that is out, however there is always some slippage so it isn't equivalent to a UIAA fall. Factor 2 falls suck, they are not fun. I took a factor 2 fall about a month ago because the rock crumbled and my nut pulled out, it was about 30feet, and to touch on the weight subject, my belayer was atleast 40 pounds lighter than me and he caught me just fine. So, now about the weight difference, as long as you have a belayer who can catch you, don't worry about it. I've had my younger brother belay me when I outweighed him by 70lbs and when I fell it picked him up about 5 feet. If you're really concerned about it, tie a sling to a tree or something and anchor yourself to the ground. If you're using an ATC you don't need to jump to catch your leader. Just catch them, the device has slippage it will be fine. If I'm leading a route and I fall, I couldn't care less if the catch is soft, I just want to be caught, and not by the ground.. But back on topic, as weight difference goes don't worry about it, and if you feel inclined anchor yourself to a tree with a long sling.
I can tell you understand fall factors, but I believe your definition more accurately describes a factor 1 fall (yes I'm nitpicking)

A factor 2 fall is when you fall twice as far as the length of rope out.

A true factor 2 fall can be avoided by clipping part of the anchor as your first piece.
june m · · elmore, vt · Joined Jun 2011 · Points: 110

Well I can tell you from personal experience that being 60 lbs lighter is an issue. I was belaying , directly below( not away from tbe cliff) the first bolt, my partner blew the 4th clip with a double arm lenght of rope out. I was yanked almost up to the first bolt. My partner went flying below me and just barely missed hitting the deck. I had no rope burn on my brake hand. I did however dislocated finger, get a huge bruise on my hip and scrapes on my arm and leg on the side opposite my brake hand and but I kept my partner off the Deck. Consequently I try to tie in whenever possible when climbing with someone who always weighs more than 20 pounds more than me , which is almost everybody since I only weigh a hundred pounds.(it was a steep climb)

Emil Briggs · · Unknown Hometown · Joined Sep 2013 · Points: 125

Chris, Jake and 20kn. Not meaning to beat the whole soft catch thing to death but I just realized that when you talk about people who have caught thousands of falls in a relatively short period of time that implies that most of those falls were not on low impact ropes (even if they were using a Beal). Reason being that the impact force of a rope goes up with repeated falls. That's true of both short term repeats as when working a crux and long term for a rope that has taken many falls over a period of months or years. The effect is actually pretty dramatic.

Arthur Torrey · · North Billerica MA · Joined Jul 2015 · Points: 46

Interesting thread... let me add a new view, albeit doing top rope belays in the gym...

I'm a paraplegic adaptive climber, working towards my lead card, but not quite there (need a partner for the lead class) I belay from my power chair, and have never had a problem catching anyone, but I'm also a heavy weight, probably in the 250lb range with all my gear on...

Other folks also haven't had a lot of problems catching me, or even holding me while getting gear into shape to be lowered.... Again this is top-roping w/ gym rope...

Flip side, I belayed a little kid (maybe 50lbs?) on an adaptive kids day. He was a 'natural' and on his final climb sent a 50' 5.8+ - and I had to FEED rope into the belay device to get him to lower, as he was almost outweighed by the rope on the down side....

I will admit to being a bit more worried when I start leading and lead belaying - I can't do a 'soft catch' since that would mean being yanked out of my chair and landing who knows where (possibly on the chair crooked...) I also suspect that because of my weight, any belayers for me will need to anchor... Again minimal soft catch....

Interesting problem....

eli poss · · Durango, CO · Joined May 2014 · Points: 525
Arthur Torrey wrote:I will admit to being a bit more worried when I start leading and lead belaying - I can't do a 'soft catch' since that would mean being yanked out of my chair and landing who knows where (possibly on the chair crooked...) I also suspect that because of my weight, any belayers for me will need to anchor... Again minimal soft catch.... Interesting problem....
Dude, that amazing. Not letting a wheelchair stop you from climbing is really inspiring. If you can adapt enough to climb 5.7 at the Gunks, you are most definitely adaptive enough to figure out a way to give a soft catch.
Aleks Zebastian · · Boulder, CO · Joined Jul 2014 · Points: 175

climbing friend,

With my considerable neck and back meat and most excellent pulling power, I often pull light belayer off ground during bold flash attempt that does not going so well.

If I have a light belayer and may be hucking my meat off sport climb, is it better to unclip first draw or not, and may it be better to have them stand directly under first draw or not?

you may be thinking they stand under first draw. however if they stand back, does it not add a rope bend and a liittle more friction for them to go flying less far? You see, yes?

I have same wonderings about whether you leave first bolt clipped. If yes, more friction? If no, less friction, but belayer can fly further in air when you huck your meat without getting pulled into draw, yes?

highaltitudeflatulentexpulsion · · Colorado · Joined Oct 2012 · Points: 35

You know what rarely gets mentioned in these "How do I?" threads? Fun.

It's quite possible to climb with someone substantially heavier than you. It sucks and I won't do it.

After my post coffee good morning dump and a respectfully nervous pre-climb piss (slim 2004), I weigh less than one of Aleks's cheesesteaks. It sucks climbing with heavy people.

I don't climb with people more than 40 over me. I'm not worried about dropping someone, I just don't want to deal. I do this for fun afterall. I'll belay you on TR, on your rope (which I'll cut if you break off a crucial hold).

Guideline #1: Don't be a jerk.

General Climbing
Post a Reply to "Maximum weight differential between belayer and…"

Log In to Reply

Join the Community

Create your FREE account today!
Already have an account? Login to close this notice.

Get Started.