Mammut Smart Belay Device Review

For the last 18 months or so I’ve been using a Mammut Smart belay device, an ingenious autolocking belay plate designed for sport climbing and indoor use. Seeing as climbers are naturally pretty conservative when it comes to gear, the device has met which a fair bit of scepticism from my partners however I’ve come to really rate it. Here are my thoughts.

Mammut Smart Belay Device

The Mammut Smart is unusual for an autolocking belay device in that it has no moving parts. Instead it consists of two drumstick shaped plates riveted together with a slot for a large HMS karabiner. Sandwiched between these plates are two polished metal braking surfaces and an ergonomic plastic handle. One concern I’ve seen raised about the Smart is the use of plastic on a surface over which the rope runs. All I can say to this is that I’ve belayed hundreds of routes and caught hundreds of falls with it and the plastic shows absolutely no sign of wear.

Inserting a rope into the Smart is very quick and, thanks to the devices unusual shape, should you insert it the wrong way round it’s blindingly obvious. A loop is inserted between the two braking surfaces and a karabiner clipped through the slot and loop. The dead rope then runs down a slot in the handle. One set up tip I’d offer is to use a captive eye karabiner, like the Black Diamond Gridlock, or one with a sleeve to prevent cross loading, like the Element Smart HMS, as the devices design does make cross loading very possible and it’s one less thing to think about.

In use the Smart is held with the handle in the crook of your thumb and your hand wrapped around the handle and dead rope. This hand is able to quickly adjust the friction of the device with only very small movements of the hand. The other hand is free to pull rope through the device and once the technique is mastered it is very easy to pull rope through the device. Far easier, in my experience, than pulling rope through a GriGri or Eddy.

The plate locks when the karabiner is pulled forward and upward onto the two braking surfaces tightening the rope into a omega (Ω) shape and producing enough friction to completely lock most single ropes (I’ve only used it down to 9.4mm and it was fine at that diameter). Unlocking the device is weirdly counter-intuitive if you’re used to normal belay devices as it involves pushing the handle away from your body, a very different motion to any other system I’ve used. With care you can unlock the device smoothly under load however there is a definite tendency for there to be a small initial jolt at the start of a lower – possibly not ideal for belaying nervous partners.

Catches with the Smart tend to be a little more dynamic than with a GriGri or Eddy which is good from a comfort point of view but does result in the climber falling a little further. Once locked off the Smart provides plenty of friction so there is minimal rope creep on long redpoint sessions – this is a massive improvement over the superficially similar but massively less effective Wild Country SRC.  It’s also easy to take in and lock off the Smart quickly should your partner require assistance getting back to the bolt after a fall.

Lowering is one area where the Smart does lose ground to cammed devices like the GriGri; because there are three variables, angle of the device, tension on the handle with your thumb and grip on the rope with your hand, which control the speed of lowering it can be hard to give a completely smooth descent. I’ve never found this to be a problem when I’ve been lowered on the Smart and my partners haven’t complained  so for me this isn’t an issue.


I really rate the Smart. In fact I’d certainly say that it’s my first choice device for sport climbing and the wall. It is easy to use, after a short learning curve, and provides comfortable catching, locking and lowering whilst being incredibly light and simple. Were I buying again I’d certainly struggle to pay more than twice as much for the GriGri I used previously.

Other Autolocking Belay Devices Used/Owned:
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4 thoughts on “Mammut Smart Belay Device Review

  1. Good review and description, still very intrigued on how it works and feels. Would be useful for my trip to Mt Blanc and the Matterhorn in Aug.

  2. It’s great to see one that is actually designed for sport climbing and be interesting to see what the feel is when lowering off.

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