The belay device is the cheapest piece of climbing gear that has the most direct impact on safety. A 30 dollar tube device or a 90 dollar GriGri is what stops a 200 pound climber from hitting the ground. The choice between the two main categories (tube devices and assisted braking devices) is not just about price. It is about what kind of climbing you do, how you learned to belay, and what you climb most often. Picking the wrong category leaves you either over-protected with a heavy device on an alpine route or under-protected with a tube during a long sport projecting session. Here is how the two categories actually compare.
How belay devices work
A belay device is a friction tool. It forces the rope through a tight bend that the belayer can hold against the climber’s weight using a fraction of the actual fall force. The two main mechanisms are passive friction (tube) and active cam (assisted braking).
A tube device is a passive piece of metal with two slots. The rope passes through both slots and around a carabiner attached to the belayer’s harness. When the brake strand is pulled down, the rope bends sharply over the carabiner and friction multiplies. The belayer must hold the brake strand down at all times to catch a fall. If the brake hand releases, the rope runs free.
An assisted braking device (ABD) uses a movable cam that pinches the rope when load is applied. When a climber falls, the cam pivots automatically and clamps the rope against the device body. The brake strand is still required for normal slack management, but if the belayer is distracted or makes a mistake during the fall, the cam usually catches the rope anyway.
The first generation of ABDs (Petzl GriGri, introduced 1991) revolutionized sport belaying because long working sessions on a route could be done without the constant attention required by tube belaying. Modern ABDs (GriGri+, Edelrid Pinch, Mammut Smart 2.0) refine the original concept with better cam geometry and lighter materials.
What tube devices do well
Weight. A tube device weighs 60 to 80 grams. An assisted braking device weighs 105 to 200 grams. On long alpine routes where every gram counts, the tube wins.
Versatility. A tube can belay two followers simultaneously in guide mode (also called auto-block mode) by clipping the device directly to the anchor with the rope strands locked in a special configuration. Most ABDs cannot do this.
Rope handling. Tubes feed rope faster and smoother than ABDs because there is no cam to override. Sport leaders pulling slack to clip a quickdraw above their head get the rope they need instantly with a tube. Some ABDs require an extra finger movement to override the cam during fast slack pulls.
Rappelling. Tube devices are the standard for rappelling. They handle two rope strands simultaneously and provide smooth, controllable descent. Most ABDs handle single-strand rappel only or not at all.
Cost. 25 to 45 dollars for a quality tube. 55 to 95 dollars for an assisted braking device.
Examples: Black Diamond ATC-XP, Black Diamond ATC Guide, Petzl Reverso, DMM Pivot.
What assisted braking devices do well
Safety backup during distractions. If the belayer looks away, the cam catches the rope. This is the most important benefit for the most common climbing scenario (sport climbing where the belayer chats with friends).
Comfortable hangs. When the leader works a move and hangs on the rope, the cam holds the weight automatically. The belayer does not need to grip the rope tightly for minutes at a time.
Top rope safety for new belayers. A climbing partner who is still learning to belay benefits from the cam as a backup. Most gyms now require or strongly recommend assisted braking devices for top rope.
Sport leading. The dominant use case for ABDs. Multiple falls per session, lots of hanging while working sequences, and the consequences of a missed catch are severe.
Lead falls catch consistently. The cam engages whether or not the belayer’s brake hand is in position. Tube devices require correct hand position 100% of the time.
Examples: Petzl GriGri+, Edelrid Pinch, Mammut Smart 2.0, Wild Country Revo.
What you give up with each category
Tube device for sport projecting. Long hangs require constant brake hand grip. Belayer fatigue increases the risk of dropping the brake strand. Less safety margin if the belayer is distracted by a phone, partner, or weather.
Tube device for new belayers. No backup if the brake hand moves out of position. Most gym belay accidents happen because a new belayer let go of the rope at the wrong moment.
ABD for alpine routes. Extra weight in the pack. No guide mode for belaying followers. Often does not handle thin twin or half ropes well below 8.5 mm.
ABD for fast slack management. Some ABDs hesitate when feeding rope rapidly upward (during a leader clipping a quickdraw above their head). The result can be a short pause in slack delivery that the leader feels as a tug. Modern ABDs (GriGri+, Pinch) have improved this significantly.
ABD for rappelling. Most ABDs only handle single-strand rappel. A standard double-strand rappel requires a tube device or a Munter hitch.
The decision matrix
Gym climbing only: Assisted braking device. Most gyms require or recommend them. Petzl GriGri+ or Edelrid Pinch.
Outdoor sport climbing, single pitch: Assisted braking device. Safety margin during long sessions.
Outdoor sport climbing, multi-pitch: Assisted braking device for the leader, tube for the follower (the follower can use guide mode on the belay).
Single pitch trad cragging: Either works. Most experienced trad climbers prefer a tube for the rope handling. New trad climbers benefit from an ABD as a safety backup.
Multi-pitch trad and alpine: Tube device with guide mode. The Petzl Reverso or Black Diamond ATC Guide are the standards.
Ice climbing: Tube device for the leader belay (rope handling and weight matter). ABDs sometimes struggle with frozen and icy ropes.
Big wall climbing: Both. The leader uses an ABD for long hangs while aiding. The follower uses a tube in guide mode at the belay.
First belay device: Assisted braking device. The safety backup outweighs every other consideration for a beginner.
Common mistakes
Holding the cam open during lowering. The biggest cause of GriGri accidents. The thumb pushes the lever fully open while gripping the device, which disables the cam entirely. Use the lever with thumb and finger only, never with a full grip. Practice lowering on the ground before doing it on a real climb.
Trusting the cam blindly. ABDs are not panic-proof. They can fail to engage if the rope is fed in the wrong direction, if the belayer is in the wrong position, or if a foreign object jams the cam. Always brake hand control the rope, even with an ABD.
Using the wrong rope diameter. Each device specifies a rope diameter range. The GriGri+ handles 8.5 to 11 mm. The Pinch handles 8.5 to 10.5 mm. A 7.7 mm half rope cannot be safely used in a device built for 8.5 mm minimum.
Skipping the partner check. Before every climb, both climbers check each other’s harness, knot, and belay device. Most climbing accidents happen because of a setup error that a partner check would have caught.
Mixing brake-hand habits. A belayer who learns on an ABD and switches to a tube without proper training is at risk. The brake hand technique for a tube requires more attention than for an ABD. Take a few sessions with an instructor or experienced partner to relearn the habit.
How to decide for yourself
Three questions:
- What is your dominant climbing style. Sport and gym, lean assisted braking. Alpine and multi-pitch trad, lean tube device.
- How attentive will you be while belaying. If your sessions involve long conversations or phone use, the ABD safety margin matters more.
- Do you climb with a partner who needs the backup. New belayers and climbers learning together benefit significantly from ABDs.
The 2026 reality is that most climbers eventually own both. An assisted braking device for sport and gym, and a tube device for alpine, multi-pitch, and rappelling. For a first device, the ABD wins on safety margin alone. The 50 to 60 dollar premium over a tube device buys a meaningful reduction in the most common belay errors.
Frequently asked questions
Is the GriGri safer than a tube device?+
In real-world use, yes for most climbers. Accident analysis from the American Alpine Club shows that the most common belay error is the belayer releasing the brake hand during a fall. Tube devices require constant brake hand control. The GriGri's assisted-braking cam catches the rope automatically when loaded, providing a backup if the belayer makes a mistake. The qualifier is that the GriGri is not a panic-proof device. Improper technique (especially over-riding the cam with the thumb during lowering) has caused fatalities. The device is safer than a tube only when the belayer uses correct technique.
Can I use a GriGri for trad and multi-pitch climbing?+
Yes, with caveats. The GriGri works well on multi-pitch sport routes and trad routes with a fixed belay. It does not belay a follower in guide mode (auto-blocking mode), which limits its use on long alpine routes. It also weighs 175 grams compared to 60 grams for a tube device, so weight-conscious alpinists prefer tubes. For pure single-pitch sport and most cragging, the GriGri is an excellent choice. For long routes with rope ascending or guide-mode follower belays, a tube device with auto-block capability (Petzl Reverso, Black Diamond ATC Guide) is better.
How do I lower a climber smoothly with a GriGri?+
Use the right hand on the brake strand and the left hand to gently open the lowering lever. Modulate the lowering speed by feathering the lever with thumb and finger, not by gripping the lever fully. Keep tension on the brake strand at all times. If lowering becomes uncontrolled, release the lever and the cam will re-engage. Practice on the ground first with a friend before lowering a climber from 30 meters up. Common mistakes include gripping the lever too hard, which gives a fast and jerky descent, and releasing the brake strand, which can cause the cam to lock unexpectedly.
Tube vs GriGri vs Edelrid Pinch vs Mammut Smart: which assisted braking device is best?+
The Petzl GriGri+ is the most refined and the standard for gym and sport climbing. It is 90 dollars, heavy at 200 grams, but the most intuitive. The Edelrid Pinch is newer (2022) and the lightest assisted braking device at 105 grams. It works with thinner ropes (8.5 mm and up) and is becoming popular for sport and alpine. The Mammut Smart 2.0 is 55 dollars, lighter than the GriGri, and uses passive cam geometry without moving parts. It is excellent for beginners but less smooth on lowering. For a first assisted braking device, the GriGri+ is the safest default. For weight-conscious climbers, the Pinch is the upgrade.
Can I belay an outdoor lead climber with a tube device safely?+
Yes, and most trad and alpine climbers do. The key is attentive belaying with the brake hand never leaving the rope. Tube devices allow giving and taking slack faster than assisted braking devices, which matters during dynamic falls and on long pitches. The skill required is higher than with a GriGri because there is no automatic backup. Most accidents with tube devices come from the brake hand releasing during a fall or from miscommunication during lowering. Climbers who use tubes properly have an excellent safety record over decades of use.
