Expert Review: La Sportiva Synchro AT 125 Ski Boots · 2017

Published on 09/29/2022 · 5 min readThis review is my honest opinion of the ski boots, which I purchased with my own money in September of 2019.
Alex Arnis, Ski Expert
By Ski Expert Alex Arnis

Making a jumpturn down the Needle. All photos courtesy of Alex Arnis

About this Review: This review is my honest opinion of the ski boots, which I purchased with my own money in September of 2019.

My take

I am impressed at the durability and stamina of the La Sportiva Synchro AT Ski Boot, and have been pretty stoked at the boot’s ability to navigate steep terrain almost as well as any mountaineering boot would. This is the ideal boot for advanced backcountry skiers who are looking for a lightweight touring boot, but still value quality performance on the downhill.

Boots after three seasons

About the gear

  • Model: 2018 La Sportiva Synchro AT Ski Boot
  • Size: 26.5

About me

  • Height: 5’6”
  • Weight: 140 lbs
  • Street shoe size: 8.5
  • Experience: Four years of backcountry skiing

Test conditions

  • When I bought these: September 2019
  • Days tested: Almost 30 days a year for three years
  • Skis: 2017 Salomon Rocker2 100 Skis
  • Bindings: Black Diamond Helio 350 Ski Bindings
  • Where I’ve used it: Mountaineering lines in the Wasatch
  • Terrain: Steep terrain

How they perform

Walk Mode
Claimed Stiffness Accuracy
Heel Hold

What I was looking for

I really wanted a touring boot with a lighter weight for ski mountaineering, but I also wanted one that would give me enough weight to power through the downhill.

Why I chose this gear

This boot was a good compromise between going ultra-light versus heavy and hard-charging. It was a toss-up between buying these or the 2018 Dynafit Hoji Pro Tour, but ultimately the fit was a lot better in these La Sportiva boots given my wide feet. Also, the Hojis didn’t have a toe bail, which would have meant I would not be able to attach my style of crampon.

Cruising through some deep powder in the Wasatch

What I love about them

  • Accuracy of Claimed Stiffness: La Sportiva claims a 125 flex with this boot, which I would say is very accurate as the Synchro AT keeps my feet tight and responsive during the down. I have been super impressed by this responsiveness.
  • Accuracy of Claimed Fit: It is a slightly roomier fit compared to other boots I have tried, but the Synchro AT is easily heat-molded so it’s possible to get a better, more snug feel.
  • Comfort: I have found these boots to be incredibly comfortable even after three seasons of continuous use and abuse. I have wide feet and low arches so the 102.5 mm last is perfect for my wide feet.
  • Flex: La Sportiva claims this boot has a 60-degree flex, which feels accurate and allows awesome boot packing and overall mobility on the skin track.
  • Weight: These boots weigh in at 1,550 grams, which I have found is the ideal weight for the ski touring I prefer to use them for.
  • Ease of use: I found these boots incredibly easy to pull on and off because of the large two-piece, or “Double Power Tongue”. This hinged tongue, made of Grilamid, extends all the way to the tip of the boot, and makes putting the boots on or taking them off extremely convenient.
  • Walk mode: These boots have a great walk mode and I feel like they have a flex that is extremely similar to many mountaineering boots. The Synchro AT boot has a 50-degree range of motion so I felt incredibly comfortable and mobile when boot packing.
  • Grip: These boots have an awesome grip thanks to the Vibram sole La Sportiva uses. I have navigated rocky knife-edges with them and felt comfortable and stable throughout. The sole is also super sticky on rock.
  • Durability: I have used these for three seasons and they have held up surprisingly well especially considering how hard I tend to be on gear. Boots typically last me about two seasons, but these are going on four with no major deterioration.

Issues I have encountered

  • Adjustability: The adjustability with these boots may be my biggest gripe. On the uphill I prefer to loosen my buckles and normally they stay firmly in place. The Pegasus Plus buckle, unfortunately, slides off and is dangling everywhere after a small jaunt. This forces me to either accept the dangling or tighten them more than normal.
  • Warmth: I have found these boots to be colder than others I have worn. It is not the biggest issue I could encounter, and it’s easily remedied by simply wearing a warmer pair of socks.

Favorite moment with this gear

This past March I trekked up the South Ridge of Mt. Superior and skied down the South Face. These boots worked incredibly well with crampons while boot packing the first bit, then crushed it on the downhill!

Value for the money vs. other options

These boots tend to run a bit cheaper compared to other similar options. For me, it was a tossup between these boots, the Hoji Free 130, and the Scarpa Maestrale RS. Since all these boots are past-dated models they are all running a bit cheaper than the original price, depending on your size. However, I found these Synchro AT boots were significantly cheaper than the other options. In addition, I have a wider foot and lower arches, and these boots just generally felt so much better compared to their counterparts.

These three boots are pretty similar but there are some key differences. If you are looking to prioritize downhill go with the Hoji Dynafit Pro. If you are looking to prioritize uphill go for the Scarpa Maestrale XT. However, if you are looking for that great middle ground, then these La Sportiva Synchro boots are the move.

Final verdict

Overall, these boots have served me exceptionally well for the past couple of seasons and I would recommend them to anyone looking for a great all-arounder touring boot. Any minor inconveniences I have can in no way detract from the overall solid design and durability of this boot. Can’t wait for more days to come!

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