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Mammut Smart Belay Device Review

mammut smart belay device
The Smart is the lightest weight auto-locking belay device tested.
Credit: Mammut website
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Price:  $50 List
Manufacturer:   Mammut
By Chris McNamara ⋅ Founder and Editor-in-Chief  ⋅  Feb 11, 2010

Our Verdict

The Mammut Smart is one of the lightest and lowest priced assisted-locking belay devices on the market. It is low profile, has a simple design and worked especially well for toproping. We also liked it for belaying the leader, but many testers would repeatedly short-rope us during clips.
Great value
Lowering and lead belaying not the smoothest
The Smart is a great value for an auto-locking belay device. The $30 price is less than one-third the cost of a Petzl GriGri and half the cost of the Trango Cinch. Its also one-fifth the weight of those two devices. The Smart takes some getting used to and we found many people had a hard time feeding rope fast to a leader. However, once we got the hang of it, it worked fine on ropes down to 8.9mm and up to 10.5mm a range the Trango Cinch and Petzl GriGri are officially not recommended for. Like any device, the Smart can be mastered for smooth belaying/rappelling, but it takes more work to get used to than other products reviewed. The Cinch and GriGri still handle better. But the Smart is a great value option and we loved the lightweight package.

Our Analysis and Test Results


The Mammut Smart is very light, very compact and a real value. For a day at the gym or crags, this device is a great, auto-locking belay device alternative to the standard belay device such as the Black Diamond ATC XP, which does not lock up. It is the same weight as most manual belay devices, meaning that you hardly notice it on the side of your harness.


The Smart took some getting used to. It has a tendency to lock up when throwing rope out fast to a leader. It was also one of our least favorite devices to lower with. For everyday lead belaying and lowering it works, but not nearly as smoothly as most other devices. Additionally, it does not work as an auto-block device, which the Cinch or GriGri do.

This device is recommended by its maker for much skinier ropes than the GriGri or Cinch. However, we found that the GriGri and Cinch actually locked up better on really a skinny rope than the Smart. So it just goes to show you that the "manufacturer-recommended rope diameter" only means so much. Read our the GriGri and Cinch reviews for a more detailed discussion on manufacturer recommended rope diameters.

Best Application

Belaying in the gym? Hitting the crags for a day of leading and TRing? Looking for a great auto-locking device but dont want to spend the extra cash for a Trango Cinch of Petzl Gri Gri? The Smart is a great low-cost alternative to other auto-locking devices and works on ropes from 8.9mm to 10.5mm.

Personal Stories

We took the Smart cragging in The Valley. It worked especially great for TRing. It would auto-lock off with ease, so we didnt get as worn out controlling the rope. When we handed the device to a friend to belay us, often we were short roped. It was not intuitive at first.

Chris Mac is curious to see how this works for short-fixing on big wall speed ascents. He is used to not bringing a GriGri or Cinch because they are too heavy to lead with. But the Smart is so light that it might be worth leading with and then self-belaying with while short fixing (not sure if the manufacturer recommends this).


A price of $49 for the Smart auto-locking device is a great deal. It is far less than the Petzl GriGri and Trango Cinch. It is not as versatile as the previously mentioned devices, but is great for the climber on a budget.

Chris McNamara
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