While it is possible to use most styles of locking carabiner paired with a belay or a rappel device in a pinch, certain styles perform much better at the task. HMS or pear-shaped lockers handle ropes moving around the basket of the carabiner better than small offset-D shapes, especially when rappelling on double strands, and keep them from pinching and creating extra unwanted friction. A problem that can arise when using large locking carabiners appropriate to belaying is that the carabiner can become cross loaded between the device and the harness's belay loop, reducing its strength by up to two-thirds. Enter the belay specific locking carabiner design. While nearly every climbing manufacturer makes one; the Belay Master 2 by DMM is among the most popular of these designs intended to eliminate cross loading while belaying. To achieve this, DMM has attached a removable plastic gate that swings shut and both locks the screwgate closed and captures the belay loop, keeping the carabiner from freely rotating.
DMM Belay Master 2 Review
Cons: Awkward to use, plastic clip hangs up on harness items, heavy
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Our Analysis and Test Results
The DMM Belay Master 2 is one of three belay-specific lockers that we tested, along with the Edelrid HMS Bulletproof Triple FG and the Petzl Freino. While it used to be our Top Pick for this purpose, it is no longer the one that we recommend as our favorite. It still does an effective job and securing the gate closure, as well as preventing cross-loading or 'biner rotation, but simply doesn't do these things as simply and effectively as the other competition.
Due to the fact that the Belay Master 2 is specifically designed for use with belay devices, we assessed it primarily for this function only. This is not the locking carabiner to be taken in the pack on a long overnight climbing trip into the mountains, on ski mountaineering trips or on most multi-pitch climbs. It is not intended for such uses, so would perform poorly if used for them. What it is meant for is to keep the rope or belay device from becoming cross-loaded against the belay loop, and it does a very good job at this. Less of an issue for top roping, where the slack in the rope is (hopefully) managed more attentively, the cross-loading of the belay carabiner is more of a problem while belaying a lead climber.
When lead belaying, more slack is inherently present in the system, and so the belay locker is allowed to more freely rotate if not attentively managed. We used the Belay Master 2 in conjunction with tube style belay devices like the Black Diamond ATC, as well as with a Petzl Gri-Gri, while both lead and top rope belaying, and we found it to be intuitive and easy to use. When using the pivoting plastic gatekeeper, the screw gate must be locked for the plastic gate to close, serving as a reminder that the gate is locked. The spine of the Belay Master 2 is fluted slightly, which prevents the Gri-Gri or similar device from binding along the spine.
One hindrance we noticed was that when storing the Belay Master 2 on our harness, the plastic clip pivots freely and has a propensity to catch and hook slings, cams, quickdraws, shoes, whatever was also hanging off our harness––a real annoyance. Since the gate must be screwed closed before the plastic clip can be snapped shut, it is not practical to solve this by locking the 'biner on your harness, and so for us this relegated use of the Belay Master 2 to gym climbing or at the sport crag, somewhere where we were not going to need to carry it around, or up a climb.
Ease of Unlocking and Locking
The Belay Master 2 is not the easiest locker to open and close, as there are more moving parts to secure the gate into place for use. Because the pivoting arm must open completely to unscrew the gate, it is much more cumbersome to leave the belay device and locker attached to the rope in between climbers as is often done in indoor or outdoor top roping sessions.
Other lockers, such as the Black Diamond Vaporlock Magnetron, work well as belay lockers for Gri-Gri devices, and are much faster to open and closed. Some users, particularly those with larger hands, found it awkward to open the gate while the gate keeper was open, and were concerned about dropping it while high on the cliff. We agree, and would feel more vulnerable taking this carabiner on and off our belay loop on long routes.
The downside to this closure is that to stow the locker away on your harness without the plastic gate keeper at risk of popping off while climbing, the carabiner must be locked and unlocked each time, an annoying task if doing anything besides single pitch climbing.
Compactness and Weight
The DMM Belay Master 2 is the heaviest locking carabiner we reviewed, and when considering the plastic gate closure system, is also the bulkiest. That didn't make too much of a difference to us considering that we were typically only using this carabiner when climbing in areas with pretty short approaches. The weight comes not only from the addition of the gatekeeper, but also from the heavier stock used. The Belay Master 2 is hot forged and has I-beam construction along the crotch and spine, but the basket is a thicker, rounder stock with a soft angle leading into the spine, making for a durable and long lasting carabiner, something you want when using it as a belay carabiner.
When it comes to gate security, it is hard to beat the system in place on the Belay Master. Numerous steps are needed to open or close this locker, and there is a very simple visual indicator — the plastic gate is hanging open — if you have failed to secure it locked all the way. That said, it is much more difficult to close than a simple auto-locker, which also has virtually no chance of coming open on its own, either.
The Belay Master 2 has adequate clearance to clip into assisted braking belay devices like the Petzl Gri-Gri, as well as into tube style devices that require capturing one or two strands of rope as well as the keeper wire. Due to the plastic gatekeeper restricting where you can place your hand, the Belay Master 2 can feel easy to fumble when trying to clip large diameter gym ropes, and feels like it has a smaller useful clearance than it would seem at first glance. It's opening was considerably smaller than our Top Pick for belaying, the Edelrid HMS Bulletproof Triple FG.
The obvious best place to use this locker is while belaying at a single pitch crag or the gym. As the heaviest and bulkiest locker, and considering the issues with the plastic gate remaining open as it hangs on your harness, we did not like using it in multi-pitch circumstances, and it is not designed to be used for building anchors or on the end of a personal anchor system.
At $22 retail, the Belay Master 2 is one of the most affordable belay-specific lockers, making it a reasonable choice for one who is considering affordability above all else, and understands its particular limitations.
This is a locking carabiner specifically designed for use with belay devices to keep them from cross loading against the belay loop, thus reducing their strength. In gym climbing and sport climbing applications, this carabiner could be a useful addition to your kit and could help improve your margin of safety. For climbers looking for a carabiner to use in a broader variety of situations, we recommend checking out a standard HMS/pear style locker, such as our Editors' Choice winning Petzl Attache.
— Andy Wellman