The Petzl Sum'Tec is a true hybrid of a traditional ice axe and an ice tool. It's the brainchild of the late Uli Steck (with influence from Kilian Journet and Colin Haley, and others) who wanted a lighter less technical ice tool that could perform the basic functionalities of an ice axe, without giving up a pick that offers a high level of technical performance. Whether looking to bring one or two for basic glacier climbs or steep north faces, the new Sum'Tec was born out of that desire.The Sum'Tec features the same modular head that is on nearly all of Petzl's other traditional ice climbing tools but with the shaft and spike of a more typical ice axe (featuring only a moderate amount of bend). The Sum'Tec also sports a well-designed slider pummel for hand support on closer to vertical routes and a full-sized spike to help facilitate driving vertically into the snow. All of this means the Sum'Tec is built for technical mountaineering routes and is our Top Pick for such routes; it's the best model modular ice axe we have ever used.
Petzl Sum'Tec Review
Compare prices at 2 resellers Pros: Climbs steep ice extremely well, sweet slider pommel, one of the best performing adzes in the review, chops ice like a champion
Cons: Self-arrest performance is good but not great, heavy for basic mountaineering, expensive
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Our Analysis and Test Results
Our favorite modular ice axe, the Petzl Sum'Tec, has the shaft of an ice axe with the head of an ice tool, and is built with versatility in mind. It takes the same head that is commonly found on most of Petzl's other more traditional ice tools and attaches it to a more a classic, albeit slightly bent ice axe shaft. The result is a lighter than average ice tool that can perform all the duties of a traditional ice axe while also functioning as an ice tool on moderate routes.
The Sum'Tec is a solid choice for general mountaineering routes and excels when the terrain gets steep or complex. Its only small drawback for moderate mountaineering routes is it features a reverse curve pick, is a few ounces heavier than many general mountaineering models, and is a touch overkill for basic snow climbs. The reverse curve is not as useful as a classic positive pick on mellow routes with little or no steep terrain. It performs well in conjunction with a second ice tool for more sustained routes and can even ascend moderate ice when a pair is utilized.
The Sum'Tec was a top performer in nearly every category, but due to its aggressive reverse curve pick, performed moderately at self-arresting. The Sum'Tec could easily self-arrest even the firmest of snow, but the reverse curve pick made it less smooth, feeling "jerky" or "bumpy". This is not something that was limited to just the Sum'Tec, as other models with reverse curve picks like the Petzl Gully, CAMP Corsa Nanotech, or the Black Diamond Venom experienced similar results.
Why the reverse curve pick you might ask? This style pick is what makes the Sum'Tec excel in steep snow and ice, even under the firmest of conditions. While the reverse curve pick takes a little tiny bit away in its self-arrest performance, it outweighs it by adding a ton of steep climbing prowess.
All of our testers appreciated the slightly bent shaft of the Sum'Tec and felt it added nice leverage while self-arresting, increasing chances of success. Overall, the Sum'tec self-arrested similarly to the Black Diamond Venom, while the Grivel Evolution or the Petzl Summit Evo offered superior performance.
Digging and Step Chopping
Due to this model's modular head, the Sum'Tec can be fitted with an adze or a hammer depending on the objective and the time of year. This was the only such model we tested that featured a modular adze/hammer. We appreciate these features for glacier mountaineering, as we tend to use the adze until mid-summer when the snow is softer, and you are more likely going to be forced to dig T-slots/deadman anchors. Later in the summer as the snow becomes firmer, you are more likely to have to pound pickets in vertically.
For comparison's sake, we analyzed how well the Sum'Tec's adze digs anchors, hacks tent platforms, and chops steps. The result? It performed like a champion and was one of the best performing models in our review in this category, even in the firmest of snows.
Use As Improvised Anchor
The Sum'Tec offers high performance in this metric. For "T-slots" or deadman style anchors, the Sum'Tec carries a CEN-T rated shaft and is more than adequate for use as an improvised anchor during crevasse rescue or for belaying of it while ascending steep snow or ice. The hole in the head of the axe is easy to clip and will load carabiners in a decent orientation. The Sum'Tec's spike is also exceptionally well-designed and helps facilitate driving the axe in vertically; this makes it easier to back-up a seated stance, improve the strength of a deadman picket as a Saxon's cross, or increase a climber's security in Piolet Manche (self-belay position).
Steep Ice and Snow
Steep snow and moderate alpine or waterfall ice climbing performance is where the Sum'Tec truly excels, earning it a high score in this metric. Our testers used the Sum'Tec on a wide range of technical routes for over two dozen days in the Cascades, Alaska Range, and the Canadian Rockies. Because of its top-tier pick, curved shaft, and well-designed slider pommel the Sum'Tec climbs steep ice efficiently. In fact, it climbed WI 3-4 well, almost to the extent of that of a traditional ice tool.
This model climbs steep terrain so well thanks to its head, which is identical to the rest of Petzl's ice tools (originally an idea of the late Ueli Steck); this means the Sum'Tec is interchangeable with the picks on the rest of Petzl's ice tools, which are among our favorite on the market. Ueli wanted an extremely capable tool that was as light as possible; because the pick is the basis for an axe's ability to climb and add security in steeper terrain, he initially asked Petzl to make him prototypes, where the head of a Quark ice tool was attached to various lightweight ice axe shafts. This design was subsequently pushed for by Alpinist Colin Haley and was also the basis for the Petzl Gully.
The Sum'Tec comes with Petzl's ice pick which is their slightly less aggressive waterfall ice climbing oriented pick. It features a reverse curve pick, just like the picks of nearly all ice tools. Like all of Petzl's technical picks, it's hot-forged and provides excellent purchase in all conditions, no matter how firm.
All of our testers really liked the Sum'tex's slider pommel. This model used to be the only ice axe that offered such a feature, but Black Diamond just added (new for 2018) a similar feature to their Venom, which is this tool's closest competitor.
Once slid into place, the slider pommel provides enough support and increased accuracy for swinging into full-on water or glacial ice, but also easily moves out of the way while plunging it into softer snow or while walking on glaciers. The Sum'Tec is slightly bent at more of an angle than most models, and this bend in the shaft kept our hands drier and out of the snow while climbing in low-dagger/Piolet Panne and mid-dagger/Piolet Appui positions, providing more than enough clearance on moderate to even steeper ice.
Overall, no model climbed steep snow or ice as well. The Sum'Tec is a slightly less aggressive than average ice tool but still has even curvature, which would have been considered hyper-aggressive just over a decade ago. The Sum'Tec is a noticeable step up from the Venom, primarily because of the Sum'Tec's weighting and pick. However, the Black Diamond Venom climbs steep snow and ice the next best in our review.
Comfort to Carry
Comfort to carry is one category where the Sum'Tec underperformed, though average overall. Like many European based models we tested, the Sum'Tec is more comfortable in self-arrest/Piolet Canne (pick-forward) position than it is in self-belay/pick backward. The overall shape of the head is excellent, but when using with bare hands or thin gloves in self-arrest position, you can feel some of the teeth that are closest to the shaft.
This design was hardly uncomfortable, though it wasn't quite as good as other models geared more towards comfort like the Black Diamond Venom, Raven, or Swift.
At 17 ounces, the Sum'Tec is slightly heavier than most mountaineering axes but not by much; for those that need it, it certainly brings plenty of performance for the 2-5 extra ounces. The Sum'Tec is tied for the lightest CEN-T/UIAA Type 2 rated axe in our review; the Black Diamond Swift also weighs 17 ounces, though it's worth noting that it does not feature a modular pick.
When compared to this model's closest competition, the Black Diamond Venom is 18 ounces and only CEN-B/UIAA type 1 rated (though we believe this is primarily because of the pick).
It is about 2-4 ounces heavier than most other general mountaineering axes but remains lighter than the Black Diamond Venom and many other modular axes on the market. While it isn't super light, it does feature an interchangeable reverse curve pick, a CEN-T rated shaft, and a slider pommel.
The Sum-tec is more expensive than the similarly designed Black Diamond Venom; however, for that extra fifty dollars, you get a higher performing hot-forged pick, an ounce of weight savings, and a modular adze. Plus, you get an ice axe you can use to climb moderate water ice with rather than just steep snow. Adding to the value, if you already own Petzl ice tools or are considering a pair, it's nice that the picks, hammers, pick-weights, and adzes are all interchangeable between models.
The Sum'Tec is the best option for folks who want a more technical ice axe or a lighter-weight ice tool for moderate routes. The Sum'Tec is stellar for a wide-range of mountaineering and alpine routes that truly blur the line between an ice axe and an ice tool. It can be used independently for basic glacier climbs, provides security on steeper snow routes, and can be used as a pair for steep alpine climbs, moderate alpine, and waterfall ice. Its weight and price mean it might be a little overkill for climbers who tend to stick to easier mountaineering routes and simple glacier climbs; however, a few ounces aside, the Sum'Tec remains a viable option for those routes.
— Ian Nicholson