I was climbing with someone recently and they complained that there was too much slack any time the line wasn't completely taut. By the same token when they were belaying me it was almost hard to climb because it felt like the rope was pulling me off the wall the whole time.

How much tension/slack should there be? Is there a good safe "zone" or is it just purely personal preference?

Edit: Generally I am not climbing more than 30' and I'm climbing indoors. I apologize for the vagueness. I'm just very new to climbing.

  • hey - part of why people are having a hard time giving a concise answer for this is that there are vastly different scenarios where one may be toproping, and the answer changes between them. Are you talking about gym-climbing (or climbing outside on 50' or less cliffs, where the route doesn't traverse, and there aren't ledges in the middle of the route)? Because there is a simple answer for that question. :)
    – DavidR
    May 14, 2013 at 14:18
  • I'm too much a noob to ask the nuanced version. For instance, what is traversing? May 15, 2013 at 13:28
  • When the route moves sideways instead of straight up and down. It introduces the chance of swinging. It esp becomes an issue on routes that weren't intended to be toproped - a route may traverse 15' or more, and introduce wild swings. A route that was a safe lead may have a pendulum that could result in hitting the ground or a buttress of rock. Sometimes.
    – DavidR
    May 15, 2013 at 14:10
  • Thanks for clarifying the length of the routes... The same day you posted this, someone asked a different question about toproping 200' routes outdoors. I (at least) was thinking in those terms when I saw your question. :)
    – DavidR
    May 15, 2013 at 14:40
  • @RussellSteen The first couple times I belay for someone I ASK THEM how much slack they want. My lady never wants to feel the rope tug at her at all. But another friend always wants to feel a little tension, for his own mental security. Just ask. Similarly, you should expect your belayer to listen to what you want. That is their job. Jun 18, 2013 at 20:43

3 Answers 3


Like with most climbing related questions, I personally find it hard to give a definitive rule that applies to all circumstances. There are a couple of safety factors to consider, as well as the perception of the climber. Don't venture out on your own if any of the following doesn't seem intuitive to you.

Keep in mind the following:

  • Rope stretch: Rope stretch is a combination of the climber's weight, the amount of slack given, the steepness of the climb, the dynamic properties of the rope, and how much rope is out. For example: A heavy climber at the bottom of a long, steep route with a dynamic rope and plenty of slack means there is going to be a lot of rope stretch. If you are not very experienced at belaying a climber on top-rope, a good exercise for both you the belayer and the climber is to approximate the maximum amount of rope stretch for that climber on that specific route before he/she begins to climb: Have him/her sit in his/her harness and observe how far the rope stretches. Factor in some additional distance if you are giving a lot of slack.

  • Obstacles on the route: If the climber falls and weights the rope, are there any obstacles he or she might hit. Obstacles on a route might be a ledge below, a wall to the side, or the top of a roof if the climber has climbed above one. This is not a definitive list of all possible obstacles you might encounter while climbing.

  • How experienced is the climber: An experienced lead climber most likely knows how to take a long fall and will react appropriately to obstacles on the way down. A novice climber on the other hand might even have trouble sitting in his/her harness without awkwardly swinging into the wall. Don't assume, ask!

If all of the above is taken into consideration and the anchor is bomber, it is perfectly fine to give a climber several feet of slack, if and only if he/she is asking for it.

My rule of thumb boils down to: Give the climber what she needs. Most of the time this means, if he wants to be kept tight, keep him tight, if she wants slack, giver her some slack. Sometimes giving the climber what he/she needs means ignoring what he/she sais, and doing what is safest: A cocky climber might want more slack just off of a ledge. An inexperienced climber might want to be kept tight after just having cleared a roof with a lot of rope out, which could result in injury when the feet don't have anything to push against but when the first body-part that does is the face when it hits the top of the roof (it might be best to altogether avoid situations like the latter with inexperienced climbers.)

As a closing remark: Make sure there is at least one experienced climber at the craig setting up the top-rope and overseeing the belaying. That way, if the climber is asking for slack because he/she is getting pulled off the rock and the belayer is unsure if that is a safe thing to do there is someone to address the situation. Some situations might even warrant a spotter, if there is a lot of rope stretch and an uneven landing.

  • 1
    +1 Good answer - it eventually boils down to what the climbers asks for. May 13, 2013 at 23:41
  • Everything here is familiar to me except for: "An inexperienced climber might want to be kept tight just having cleared a roof with a lot of rope out, which would result in face and roof meeting with great force." Would you elaborate?
    – Mr.Wizard
    May 14, 2013 at 12:21
  • 1
    @Mr.Wizard: I was trying to find an example where it might be beneficial to give a little more slack. A climber who falls right above a roof might, due to rope stretch, fall to a hight where, when he/she swings back into the wall, the feet might be below the roof, while the head is still at the hight of the roof, which could result in the head slamming into the wall. I'll edit the question to point out that this is more of a hypothetical situation.
    – DudeOnRock
    May 14, 2013 at 18:47
  • @Don Branson "what the climber asks for" -> With the caveat that a total beginner might ask for something that's unreasonable or unsafe. When I belay beginners I explain to them why they might NOT want to have the rope too right (In Squamish, that's mainly relevant for slab routes where too tight a rope prevents you from fully weighting your foot on the slab and makes it more likely for you to skid off.)
    – Lagerbaer
    May 18, 2013 at 3:40
  • @Lagerbaer - Yeah, they generally like it taught. I've never see in be a safety issue, but it can interfere with movement. May 18, 2013 at 14:10

It's a bit of both.


When toproping, an experienced belayer should have the necessary training to adjust slack/tension depending on the route itself. For example, to avoid any swings that would crash the climber into the rock.

There are many examples on safety-related criteria for determining tension (safety for both the climber and the belayer), but the list is long and I don't think I'd be able to sum it all here, so I won't be listing examples.

Learning to belay requires you to learn many things, and actually teaches you to think differently about safety and security. It's also a lot of fun and very exciting.

Do consider taking proper training for this though; it's a good investment. If available, face-to-face training is irreplaceable, IMO. There are many books and videos but you'll gain more experience by discussing with other people.

And regardless of whether you get face-to-face training or not, my advice is always the same: keep asking, always assume someone knows something you don't, never take an answer blindly as true, read, research, ask again, ask more.

Personal preference

Safety issues being said, the rest may be just a matter of personal preference.

If the rope is travelling perfectly in line with your climb, excessive tension might just be reassurance to novice climbers (make them feel that the rope is really there to catch them). However, if the rope is travelling sideways, for example, it's usually counterproductive for the climber. Like you say, it effectively pulls you off the wall.

Most of the experienced climbers I know (if not all) agree that you shouldn't need tension in the rope (unless the belayer identifies an actual security risk). The rationale is that the rope is there to catch you only in the event that you fall, but not to help pull you upwards (nor to help you keep balance).

When I was taught to rock-climb, the program included "trust games". These were meant to build confidence on the climber regarding the belayer, rope, harness, and the whole security chain.

Personally, I still like some tension when I feel I'm still too close to the ground but will ask for "slack" when at a reasonable height. Sometimes I'll also ask for tension when trying out the crux in a route.

TL;DR version

There might be a "safe zone" on a given route. A belayer should have proper training to identify actual security reasons for determining tension. Other than that, tension is mostly a means of providing reassurance to novice climbers (or experienced climbers who just prefer it one way or another).

  • 1
    Historically, I haven't found "proper training" to differ greatly from "proper well written answers". Training, just like internet answers varies widely in quality. The purpose of asking here is to get not just the answer, but also the community feedback on the answer to know it's quality. By gaining enough information in this forum, I am then able to determine if a trainer is a total idiot or not. "Proper training" is not a universal answer to all TGO climbing questions. May 14, 2013 at 12:50
  • @RussellSteen - I'm sorry, but that's not true. That's like saying you can learn to drive by reading about it on the internet. There's a lot of information to impart, and performing it correctly requires a combination of skill and mechanical knowledge. Even if someone did manage to write an answer that covered all aspects of the subject, the odds of someone reading it, then translating it correctly into practice on the first try is pretty low. Rock climbing (not to be dramatic) is a life-or-death game, and reminding beginners to get proper instruction is the only responsible choice.
    – DavidR
    May 14, 2013 at 13:58
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    part of the problem is that there are multiple audiences reading these questions. Experienced climbers, who just have narrow technical questions, and beginners, who don't understand the full context, and can and do miss-interpret the things they read.
    – DavidR
    May 14, 2013 at 14:09
  • @Roflo -- I think it's a tone thing. Your tone (to me) implied "don't even ask this here at all" as opposed to, "here's what you need to know to find a good trainer who can instruct you further". Make sense? (Oh, and gave you the +1, it wasn't meant to be heavy criticism and I do appreciate your answer) May 15, 2013 at 13:31
  • @DavidR -- Everything is a life or death game. Driving is a life or death game even more so than climbing, but a lot of answers can be given about technique. I think there is also a huge difference between "training" and "practice". Even with professional training the odds of turning it correctly into practice the first go are insanely low. That takes real and regular practice regardless of how you're learning and regardless of what form you get your advice in. No one should out and try a risky activity with no practice, training or no. May 15, 2013 at 13:35

It depends.

If you're in a climbing gym, or some scenario where you're belaying someone on toprope on a route that's less than 50' tall, runs straight up-and-down ( so there's no chance for the climber to swing dangerously), or crash into a ledge then the exact amount of tension is somewhat of a personal preference for the climber. The belayer should usually keep all visible slack out of the line, while at the same time not putting active tension on the climber. If there's a chance of the climber hitting the ground on ropestretch, more tension is recommended. Also, you should use more tension of the climber asks for it.

Otherwise, if the route is longer (and there's more rope and rope-stretch), or it traverses (and the climber may swing some), or there are multiple ledges during the length of the route, or if there's a lot of rope-drag (friction on the belay), then judging the amount of tension is a matter of choosing a tradeoff between different risks. The belayer may need to be a little more experienced, and be able to make judgement calls on his / her own.

  • I disagree with keeping all visible slack out in the scenario you describe - that often reduces freedom of movement and hampers climbing. I prefer a little slack, which most people seem to after they get comfortable on the wall. May 14, 2013 at 15:32
  • :) ahhh! such a preference thing. I shouldn't have answered it... I don't think you can write an answer that captures everyone's possible preferences, while also making sure that a beginning climber doesn't deck his friend.
    – DavidR
    May 14, 2013 at 15:56
  • Answering was fine. There's good content there, but the slack issue is subjective, at least in part. May 14, 2013 at 16:08
  • I'll edit. I actually keep it at the point where there is neither slack or tension, but that's a little tricky and takes experience belaying.
    – DavidR
    May 14, 2013 at 16:37

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