Woman in climbing gym

Running repetitive laps on gym climbing walls can be the perfect way to build up your strength, rev up your endurance, sizzle away body fat, and, to top it all off, have tons of fun! How cool is that!

But what if you don’t have a belay partner? In that case, you can’t go as high as you’d want, which detracts from all of the mentioned benefits. To solve this challenge, many gyms have been incorporating dozens of auto-belay devices at their climbing walls.

What do those devices offer? How do they work? And how can you safely use them? These are some of the questions that I’ll answer in this article. Let’s get going!

In this guide you will find:

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What Does the Auto-Belay Device Offer?

Men climbing

To better understand the value of an auto-belay device, we should briefly highlight a human belayer’s role.

The Role of a Human Belayer

In top-rope climbing, the climbing rope extends from your climbing harness, passes inside an anchor at the summit, and ends back at the belayer’s hands.

The belayer must pay attention to the climbing rope to ensure that there’s enough slack. As you ascend, the belayer should gradually pull the rope to pick up the slack.

But what if nobody picks up that slack? Well, in that case, if you slip off a handhold or a foothold, you’ll fall a considerable distance, which increases the chances of injuries. Does this mean that the belayer must pick up all the slack? No. Without enough slack, any fall will whip you into the wall, leading to serious fractures or sprains.

So, all in all, not everyone can perform the role of a belayer. This job demands moderate to high experience to ensure top safety.

Auto-Belay: The Automated Alternative

Let’s admit it; automated tools barely compare to human intelligence. Humans use their versatile judgment to allow for the best experience without detracting from the safety value. But I’m glad to say that the automated technology does pull up a good fight here!

Auto-belay devices are designed as circular tools that can be easily mounted to the uppermost part of a climbing wall. They come with a built-in lanyard, fitted through a special mechanism that automatically picks up the slack. This way, you can ascend on any wall without worrying about major falls.

But wait a minute. If this device picks up all the available slack, won’t that expose the climber to the risk of whipping at the wall? No. 

The mechanism is designed in a way that interacts with the real-time load. When you fall, the device will detect the sudden load increase, which will activate the built-in brakes, giving you a soft, safe descent.

How Does the Auto-Belay Device Work?

NERD alert! In this section, I’ll dive deeper into the physics behind auto-belay devices. Although this information improves your overall experience, learning it isn’t obligatory. If you’re not interested, feel free to skip to the next section where I’ll explain the most effective way to use an auto-belay device.

If you open an auto-belay device, you’ll find a nylon lanyard wrapped around a spring-loaded spool. This simple spring is what picks up the slack as you ascend, which is pretty similar to how a tape measure recoils. Fairly simple, right?

When it comes to controlled descent, things get a bit complicated. Auto-belay devices may feature one of the following systems: magnetic or friction.

Magnetic Auto-Belays

Do you recall the iconic rule of magnetism? Opposites attract and likes repel. That’s how magnetic auto-belays control your descent.

Inside the device, the lanyard wraps around a rotor that features movable magnetic arms. Around this rotor, you’ll find large magnetic bands. At rest, the magnetic arms lie tucked inside the rotor, which prevents them from repelling with the larger magnetic bands.

When the climber falls, the rotor rotates at high speed, which pushes the magnetic arms outward by centrifugal force. The two magnetic fields repel each other at this new position, which slows down the rotor, allowing you to descend safely and smoothly.

If you like this mechanism, you can’t find anything better than the TruBlue XL from OmniProGear. Even though it’s a bit expensive, it can withstand weights between 22 to 330 lbs, making it incredibly versatile.


Check Price and Reviews On Amazon


The best thing about magnetic auto-belays is their minimal maintenance. Since there is no physical friction, the braking quality won’t degrade with time. This makes them highly cost-efficient.

I also like how these systems react to the climber’s weight. As the pulling force increases, the magnetic arms will repel harder with the magnetic bands. This way, children and adults can enjoy the same level of safety.


Besides the high initial cost, magnetic auto-belays may take a second to slow you down. This is because the magnetic arms don’t extend into the repelling position unless they rotate at enough speed.

Does this detract from their safety? Not necessarily. If you have enough falling distance before reaching the ground, you’ll barely notice this flaw. But if you fall at an intermediate distance, the device may not have enough time to activate before you hit the ground.

Friction Auto-Belays

friction auto belay device diagram

Just like magnetic devices, the friction models make use of the centrifugal force.

Here, the lanyard is wrapped around a metal drum. Inside this drum, there are two brake pads fitted over a spring.

When you fall, the metal drum will rotate at high speed. This rotation will move the brake pads outwards, where they’ll directly collide with the lanyard. As a result, you’ll have a slow and soft descent.

If you prefer this system, consider the Direct Drive Auto Belay from Perfect Descent. It can handle weight between 25 and 310 lbs, which is slightly smaller than the magnetic TruBlue.


Even though these devices depend on centrifugal force, they don’t have the same lag as their magnetic counterparts. This is because physical friction gets applied right away, unlike magnetic fields, which take time to fully repel.


With time, the brake pads will inevitably wear down, affecting the belaying efficiency. This is why you have to periodically inspect friction auto-belays.

How to Use an Auto-Belay Device

Climbing gym

Whether you took the time to understand the belaying science or not, using an auto-belay device will be fairly simple.

Step 1: Double-Check Your Climbing Harness

Before attaching the auto-belay lanyard, make sure your harness is tightly wrapped around your legs and waist. Beginners often overlook this step, which ultimately exposes them to serious injuries, even if the auto-belay is working flawlessly.

Remember to double-back all your buckles. If you’re unfamiliar, this means that the webbing should be threaded through both metal loops before coming back in on itself. This way, the harness can never be undone while you’re climbing, no matter how heavy the load gets.

Step 2: Test the Auto-Belay Device

To test the auto-belay, unclip it from its anchor, and pull the webbing a couple of feet away from the wall. Now allow the webbing to retract while maintaining a tight grip. If it retracts, you’re good to go. If it doesn’t, report it and move on to another device.

Step 3: Clip the Carabiner 

As you may already know, the market is full of many carabiners that feature different opening and closing mechanisms. If you’re not sure about how to handle the device’s carabiner, ask for help.

Novice climbers may frantically clip the carabiner into multiple points on their harnesses, thinking that this will make them safer. This couldn’t be further from the truth. Most, if not all, carabiners are designed to bear the load on two ends only (at the harness and the lanyard).

Remember, never let go of the webbing before securing the carabiner to the belay loop of your climbing harness. Otherwise, the webbing will retract all the way up to the auto-belay device, making you look like a total amateur!

Before starting to climb, test the carabiner by pulling it away from your body to ensure that it can hold your weight later on.

Step 4: Move It!

After making sure that everything is secure, start climbing as you’d normally do.

It’s completely fine to be afraid at first, especially if there’s nobody standing around. In this case, don’t climb the whole wall. Stop in the middle, and let go. The device will automatically activate, which will build up your confidence. Gradually increase the climbing distance until you reach the maximum height.

Step 5: Don’t Forget to Clip the Device Back

After finishing your climbing session, unclip the carabiner, and secure it back to the wall or ground anchor. Again, if you forget this step, the lanyard will be fully retracted to the top, preventing other climbers from using it.

Other Belay Devices

Though auto belay devices had gained a lot of popularity in the recent years, if you plan on climbing regularly it is still absolutely necessary to learn how to belay. For this reason there are literally hundreds of different belay devices out there to choose from at different price points and designs. Check out our article for more info.

Final Thoughts

I don’t know about you, but I consider the auto-belay devices as the greatest invention of the climbing world. Depending on a human belayer capped our training time, which prevented us from addressing all of our weaknesses.

I know that using an auto-belay provides endless loads of fun, but I highly recommend committing to professional training programs to up your climbing skills and prepare for ascending real routes outside the gym.

Good luck!

Published by Editorial Staff

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