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 our Top Pick for its prowess for steep snow and moderate ice climbing.
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.
The Sum'tec (right) is still a capable self-arrester, but like most more aggressive ice axes with reverse curve picks, it wasn't as smooth as models with a positive curve pick, as seen here on the Petzl Summit Evo (left).
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.
While its pick wasn't as smooth to self-arrest in firm conditions, it was decent in softer conditions, which are more common when climbers "trap door" into a crevasse. Also, its curved shaft gave its user far more leverage than traditional straight-shafted models on the final stages of the arrest as the user drives their pick in and pulls up on the shaft. Here the Sum'Tec guarding against such a "trap-door" fall on the Massive Boston Glacier, North Cascades WA.
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.
This model is CEN-T/UIAA Type 2 rated and is more than adequate for use as an improvised anchor during crevasse rescue or for belaying climbers on steep snow. The hole in its head easily accepts a locking carabiner, which makes backing up a seated stance easy.
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.
The Sum'Tec's high performing adze or hammer option adds to its overall versatility. Here Adam Butterfield carries a Sum'Tec in a remote part of the North Cascades, placing pitons to rappel from if no other anchor points exist.
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.
At the core of the Sum'Tec's best-in-review performance on steep snow and moderate water ice routes are its interchangeable pick. The Sum'Tec is compatible with all of Petzl's ice climbing picks which are among our staff's favorite on the market. Unlike the BD Venom, both the Sum'Tec's adze and pick are interchangeable.
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 is originally the brain-child of the late Ueli Steck who wanted a ice axe that could be taken on long mountain routes; it also needed to be as light as possible but still with an exceptionally capable pick. The new Sum'Tec was born, and is far lighter than most traditional water ice tools but climbs nearly as well as them. Here Danny Spreafico in the terrain the Sum'Tec was meant for, on the North Face of Mt. Shuksan.
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.
Petzl's slider pommel is another foundational element of its ability to climb steep snow and moderate water ice effectively. It provides a tremendous amount of support for our hand and additional grip on what is otherwise a slightly slippery shaft. We used it both at the base of the shaft when swinging overhead like a traditional ice tool but also at mid shaft for extended periods of mid-daggering.
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.
The slider pommel is easy to position anywhere along the length of the shaft without tools; we never experienced any unexpected slips.
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.
No other model climbed steep snow or ice as well as this model did. For climbs that involved sustained sections of steep snow or moderate ice of burly complex glacier travel, the Sum'Tec is the model we'd reach for first. Here the Sum'Tec being used on an 800ft section of 50-degree snow to gain the crest of the North Ridge of Forbidden Peak, North Cascades WA.
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.
Besides steep snow and moderate ice, our testing team loved the Sum'Tec for complex glacier travel, where we were often forced to climb in and out of crevasses and belay across snow bridges.
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.
The Sum'Tec, like many more aggressive ice axes, is most comfortable to carry in self-belay/piolet canne position (pick-forward).
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.
In self-arrest position, the Sum'Tec performed slightly below average as we were forced to hold it with our hand over its innermost teeth. We have carried the Sum'Tec for countless hours on moderate glaciers; while it isn't incredibly uncomfortable, other models offered a higher level of comfort.
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.
At 17 ounces, the Sum'Tec is slightly heavy compared to others in our review. With that said, the Sum'Tec brings a tremendous amount of performance benefits for climbers or routes that require it; in these cases, the Sum'Tec was easily worth the extra 3-5 ounces of additional weight. Conversely, the Sum'Tec is a lightweight ice tool which performs nearly as well as traditional water ice oriented models.
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).
The Sum'Tec is the lightest model to feature a modular head; it's one ounce lighter than its closest competition, the Black Diamond Venom (top axe).
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 versatile and will function for a wide range of mountaineering endeavors; it's most at home on steep snow, moderate ice climbs, and complex glacier routes. While it climbs water ice respectably, we would recommend it for someone looking exclusively for a tool for that application, as they'd be better off with a heavier, water ice dedicated tool.
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 is one of the more expensive models in our review. It is fifty dollars more than the similarly designed Black Diamond Venom; for that extra money, you get better performing hot-forged pick, an ounce of weight savings, and a modular adze. The Sum'Tec presents a decent value, due to its exceptional steep snow climbing prowess and performance characteristics. IIf you already own Petzl ice tools, you're also able to swap the picks.
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 more moderate routes. It's a fantastic option for a wide range of mountaineering objectives that truly blur the line between an ice axe and an ice tool. While it is slightly more expensive than the competition, its performance justifies the difference.
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.