ProView – Petzl Sum’Tec Ice Axe

As a mountain guide, I spend a significant portion of the year using ice axes. While this item, like many others in my kit, has become a quiver item, I find myself reaching for the Petzl Sum’Tec more often than any other piolet. The Sum’Tec is a technical mountaineering axe that bridges the gap between a traditional mountain axe and a technical tool. Like any hybrid design on most anything, this axe excels in many situations, but isn’t as good as a specialty tool. I find myself using it because of the versatility the design offers in dynamic mountain environments.
The Sum’Tec plunges well into soft snow. Photo Credit: Clifford Agocs

The design features that transform a traditional axe into a technical mountain axe are well thought out: a curved shaft, adjustable pinkie pommel (Trigrest in Petzl terminology), and reverse curve pick. Petzl made the head semi-modular with the ability to replace the pick if needed, but the hammer or adze are fixed. The spike and lower shaft are simple and work well when using the axe in upright (piolet cane) position or plunging into snow. The pick is B-rated (tested to 280kg) and the shaft T-rated (up to 400kg).
The author boulders on low angle rime ice on Mt. Hood – ideal terrain for the Sum’Tec. Photo Credit: Clifford Agocs.

The curve in the shaft, plus Trigrest, plus the reverse curve pick help this axe to excel in steep mountain terrain. A reverse curve pick allows more positive sticks in ice and is easier to clean than a classic pick design. The appropriated located curve, just below the head, offers clearance when swinging the axe in a vertical ice environment, and the Trigrest offers hand support when the terrain turns vertical. While I’ve used this axe to climb AI4 comfortably, it wouldn’t be my first choice for climbs with long durations of grade 4 water or alpine ice; a technical ice tool is the right choice for this terrain.

Where this axe really shines is on routes with significant steep snow and neve, potentially with shorter steps of technical ice climbing. Again, the curve of the shaft with the Trigrest moved up the shaft allows a good grip on the axe when holding the axe in mid-dagger position while climbing moderately steep snow and neve. Ideal climbs that come to mind for this axe are the North Ridge of Mt. Baker and the North Face of Mount Shuksan in the North Cascades, and the Liberty Ridge and Kautz Glacier Ice Chute on Mt. Rainier. Obviously, how far one can push this axe into the vertical environment is a function of user competency and comfort.
The author rappels off a classic alpine route with dual Sum’Tecs in tow. Photo Credit: Niels Meyer

As a general mountaineering axe, the Sum’Tec has its place. Buyers are given the choice of a hammer or adze, and different lengths. I’m 5’11 and use the 59cm Sum’Tec adze as my general glacier mountaineering axe. With the Trigrest moved high onto the shaft, I find the shaft plunges very well into soft-medium hardness snow, and the sharp spike works well in firm snow and soft ice. The adze functions very well to chop snow for deadman style anchors, and with practice chops steps very well. I found that there was a learning curve while using the adze due to the angle change caused by the curve in the shaft. The robust steel head hasn’t been damaged over 3 years of pounding pickets (never pound pickets with the side of the shaft or the adze as you’ll either damage the axe or the picket).
Niels Meyer in a crevasse belay smiling because his two Sum’Tecs were perfect for Mt. Shuksan’s classic North Face. Photo Credit: Chris Marshall

As the terrain gets steeper and I anticipate pounding in more pickets and needing more security as I climb, I grab a Sum’Tec hammer as my second tool. I go with the 52cm version on my second tool as its less unwieldy on my pack or stored behind my shoulder strap. Again, the spike/shaft design allows me to use the hammer to pound in the other Sum’Tec vertically as a quick anchoring solution. The hammer is adequately big and shows no signs of wear after pounding in a year of pickets into very firm snow. On alpine rock and moderate mixed routes, the hammer and head weight is sufficient to pound and clean pitons. A shorter and lighter 43cm version with hammer is available, which would be a good choice for alpine rock routes where piton craft was anticipated and snow travel was minimal. The 43cm version is too short for me to use in an upright position, but works well to carry as a second tool to accompany an adze-equipped axe.
The Sum’Tec is perfect for moving quickly up firm neve as Niels Meyer demonstrates daggering in the dawn light on Mt. Baker’s North Ridge. Photo Credit: Chris Marshall

With a B-rated pick and T-rated shaft, the Sum’Tec is strong enough to be used as an anchor while buried in a deadman/T-slot configuration. I’ve torqued the picks and shafts into cracks while mixed climbing, and haven’t broken one (yet).

As noted previously, a hybrid axe won’t excel in any areas. While the Sum’Tec self-arrests adequately, the reverse curve pick provides a more abrupt and jerky arrest. Furthermore, to make an axe that excels in technical terrain, weight must be sacrificed. When climbing technical terrain, this is justified, but in moderate, non-technical mountain terrain, I grab a lighter axe. Ski mountaineering missions and basic snow and glacier terrain come to mind. I’ve used both the hammer and adze version of this axe and have had the spike come loose on both axes. The rivet that actually attaches the spike to the shaft hasn’t failed, but the ensuing rattle is somewhat annoying and discomforting. I also have cracked the metal below the hammer due to user error and having too many missed swings while pounding in pickets. As my good friend and colleague noted, I swing a hammer like lightning: I never strike the same place twice, so I attribute the failure in the metal to me and not the axe.
The author shouldering a Sum’Tec hammer on Mt. Matier’s West Buttress. This axe selection worked well for the short glacier approach and as a tool to place pitons on route. Photo credit: Brent Butler

In conclusion, the Petzl Sum’Tec is an awesome choice as the terrain gets steeper and becomes more technical. Its sweet spot is really on those long, moderately steep routes or carried as a tool for piton placement on alpine routes, but still has its place on more moderate escapades.

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Chris Marshall is an IFMGA/AMGA American Mountain Guide. He is the Lead Ski Guide for Sun Valley Trekking and works as an Alpine Guide for Timberline Mountain Guides and Mountain Madness. When work allows, he is often reminded that he loves rock climbing.

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