La Sportiva Synchro Ski Touring Boot — Review

Post by blogger | March 26, 2018      

Colby Christoff


After a tough day of skiing waist deep powder, sometimes you have to walk right into the onsen (hot spring) with your boots on.

My first impressions of the new La Sportiva Synchro boot are for the most part positive. (Also see our previous Synchro coverage.)

— For a “125 flex” the boot seemed light.
— The “catalog” range of motion claimed by La Sportiva website is 60 degrees. I find the more flex I have in my boots, the less heel risers I typically need on my bindings. I found this to be true in the boot; I was pleased with the range of motion.
— The 102 mm last provides a wider foot with plenty of room. At first I thought I had too much room, but the buckles allow you to snug up the fit while maintaining performance.

And then, a few longer term observations:

With the very slow start to the Colorado winter season, and subsequently thin snowpack, I found myself constrained to the ski resorts and small backcountry outings for the first part of my Synchro testing (prior to our recent dumps). Luckily, a Japan trip in January put an end to that and provided a very legitimate trial to authenticate this review — and I’ve been skiing the boots ever since.

The feature that stands out to me with this boot is the intermediate cuff. The intermediate cuff is the small black cuff that goes underneath the bottom three buckles. When you skin, you can leave all buckets hooked (theoretically, more on this later) and simply leave the 2nd buckle (from the top) open. By leaving that buckle open the small intermediate cuff is left disengaged, and therefore provides a wider range of motion. And, to be clear, by disengaged I mean there is there is a small “fin” in the back of the black cuff and a small slit in the larger orange tongue. When the two line up, and thus engage, the boot greatly hardens in flex, and when left disengaged the flexibility greatly increases. I thought this was a pretty slick system and was very happy with the range of motion.

Double Power Tongue as it's officially termed by La Sportiva.

Double Power Tongue as it’s officially termed by La Sportiva.

Outer tongue nests on the full length inner tongue, locking the two together when buckled for the down.

Outer tongue nests on the full length inner tongue, locking the two together when buckled for the down.

I was not particularly fond of the Synchro “Pegasus Plus” buckles. I would often find that they would be flopping around after ten minutes of skinning. Then, when I’d tighten them down to ski and I’d reach the bottom, when releasing the buckles I’d find they would often get hung up on their receiving end, and wouldn’t completely unbuckle. This resulted in time spent tightening the buckle above or below, or tightening the power strap, in order to then release the buckle. This is not a fatal flow; however, it is certainly irritating as you are trying to get out of your boots.

Not convinced on the Pegasus Plus buckles, perhaps I'll gain more respect with more use.

Not convinced on the Pegasus Plus buckles, perhaps I’ll gain more respect with more use.

Since the buckles are apt to jiggle around and come undone as you skin, I found that the buckles would sometimes lose their positioning and I would have to re-tighten or loosen their position. This is done by spinning the small “screw” feature clockwise or counterclockwise, similar to the “barrel” adjustment on some bicycle brakes. I understand the intent of all this is to keep the buckles very light, as four do add up in weight. After looking at the La Sportive boots from years past, and having friends with older models of the same boot, the newer type buckles do seem to be an improvement, but may still need some further refinement. With that said, after a long day skiing and touring, and after you are able to release the buckles, I was very pleased to see how far the tongue opens and moves out of the way for a boot that is incredible easy to get on and off.

The object at hand.

The object at hand.

Now, moving on to the downhill performance, the skiing! In a word, excellent. I used the boots to drive my Blizzard Zero G 95’s 185, Voile V8’s 185, and Liberty Schuster Pro S’s 192 (123 underfoot). I bring up the different skis because an alpine touring boot needs to be versatile, and although it would be nice to have the one ski quiver, we all seem to have too many skis for too many applications. But hey, who can blame you for having too many skis?

While using the Synchro with the Zero Gs we had rock hard ski runs with death cookies, ruts, rocks, and a little powder. I was thus able to experience a little bit of all conditions. When I pressured the tongues, they would drive the skis, when I would hit something choppy, uneven, or lose, they would give confidence that you would power through.

A couple weeks after getting the boots I was invited on a trip to Japan with some friends whom I ski raced with in college. I decided this was the perfect trip for the Synchros.

We traveled to the North Island in Japan, Hokkaido. While there we skied some resort days, while dropping out some of their backcountry gates. The snow in Japan was incredible; I had brought the Synchos along with the Schuster Pro S’s and the Voile V8’s. The Voile’s are quite light for their size; the Synchros skied those exceptionally through the powder. The real test was the heavy, stiffer Liberty’s. I skied the resort one day with the Synchros and throughout the day found untracked powder behind some of the backcountry gates. Although this was primarily untouched pow, there were still tight bumps, trees, and choppy snow. I was able to power through everything with no issues from the boots, or the skis.

Your earnest reviewer suffering through the work.

Your earnest reviewer suffering through the work.

I’ve often skied alpine touring boots that were easily overpowered, creating a feeling that you are going to go over the front of the skis. The cuff height and “stiff” flex of La Sportivas held me in place, and gave me confidence to open it up without being worried that the boots wouldn’t push back. I put “stiff” in quotes because I have skied many 150 flex plug boots, so stiff can be a relative term. For the Syncros’s class of boots I was very happy with their skiing performance and their ease of skinning.

Rear spine.

Rear spine is probably what gives beef with less weight.

The boots clipped in easily to a variety of bindings I used. From an older pair of Dynafit Vertical FT 12 bindings to a brand new set of G3 Ion LT 12’s, and the Tyrolia Adrenalin bindings too, the Synchro locked in with confidence. The tech fittings were easy to line up and clip into the Dynafit and G3 bindings, and the rubber Vibram sole of the boot, though thick, doesn’t compromise the “DIN” shape of the sole. Test for the latter, I was able to easily adjust my Tyrolia bindings for the boot.

You get used to the mode switch being opposite  most other brands.

You get used to the mode switch being opposite most other brands, but will wonder why?

Inevitably, each year there are more and more boots on the market with more and more features. It seems many boot companies try to differentiate themselves in one way or another. Perhaps that’s why La Sportiva switched the usual direction of the walk mode versus ski mode setting. As you can see from the photo, walk mode is down and ski mode is up. I believe with most AT boots on the market, ski mode is down and walk mode up. It seems odd to have switched this. I cannot say I had trouble engaging the feature nor is it confusing as to which mode you are in; however, it is odd to make this opposite of most other boots on the market.

Conclusion: The Synchro did well for me, and I’m continuing long term testing for WildSnow. My two gripes with the product are small in the overall scope. Mainly, the buckles could be better and I think we’ll see improvements to the Pegusus concept as La Sportiva progresses this project. Overall, they have designed a well thought out boot that is light and goes uphill well, while supporting strong downhill skiing.

Weights, 27.5 Synchro, BSL 304
Shell, 1244 grams
Liner, 246 grams
Boot complete, 52.6 ounces, 1,490 grams (1550 grams catalog weight)
Compare to Spectre at 51.8 ounces, 1470 (1445 grams catalog weight)

(WildSnow guest blogger Colby Christoff ski raced at Syracuse University. He moved to Colorado some time ago and explores the backcountry whenever he can escape from his job as an engineer. He appears to escape often.)


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23 Responses to “La Sportiva Synchro Ski Touring Boot — Review”

  1. Pavel Sova March 27th, 2018 11:07 am

    Thank you for the review; this boot looks nice and has innovative design.
    I have the original La Sportiva Spectre (yellow-black) and have had hard time with pressure on my malleolus bone (inner ankle). Only generous widening of the boot middle part helped some.
    I thought they fixed this in Spectre 2 (blue-yellow) but I am wondering how Synchro is in that respect.

  2. Lou Dawson 2 March 27th, 2018 1:23 pm

    Malleolus problems can often be fixed with combined interventions, everything from footbed on up through liner molding to shell punching and cutting. Don’t give up. Lou

  3. Blake March 27th, 2018 9:03 pm

    Pavel – I’ve been in the original Spectre for a few years. It nearly destroyed my inner ankle as well. I found that the original liner has 3 seams that come together right on top of my ankle – exacerbating a pressure point.

    I switched the liner out for an Intuition liner and the problem was solved.

  4. Kristian March 28th, 2018 7:15 am

    Pavel, the very first original 2013/2014 La Sportiva Spectre was an absurdly low volume design.

    They then labeled the remaining stock Low Volume and for 2014/2015 created a higher-volume instep.

    Honestly, I think that they should have recalled and replaced all of the 2013/2014 Spectre boots.

    Personally, I felt cheated and had horrible pain that went away with the higher volume model.

    Any one buying the yellow/black La Sportiva Spectre should be extremely cautious about ending up with the original low volume model. They will feel find at home/store but be terrible touring uphill.

  5. VT skier March 28th, 2018 7:38 am

    How do you identify whether one has the early 2013/2014 Spectre, or the higher volume, later version?
    I have a pair of the Black and Yellow Spectres, and have fit problems over my instep.

  6. Kristian March 28th, 2018 7:57 am

    No idea; they look identical to me.

    Call La Sportiva JONATHAN LANTZ and ask for replacements.

  7. Pavel Sova March 28th, 2018 10:52 am

    Thank you all for your excellent responses – the collective wisdom is one of the aspects that makes Wildsnow so amazing.
    I guess the ankle hurt in Spectre 1.0 is dependent on the prominence of the malleolus bone which varies amongst us humans. Mine is significant but I was able to fix it to manageable using a heat gun and large wine bottle (it seems to me that it is a temporary fix becase the plastic has a memory). I should also say that medium footbed helped, too, while ankle punch or changing liners for Scarpa’s Intuition ones did not. I don’t have low instep issue but I think heat gun and smaller bottle will fix that as well. Other than that the boots feel good, ski well and I like the La Sportiva innovative design but if I buy the next boots I don’t want to spend a lot of time and $$ fixing it. But it seems that La Sportiva addressed the problem in later iterations of Spectre and now hopefully in Synchro.

  8. Jean Marc Emard March 28th, 2018 5:36 pm

    I have skied lots in Spectre 2.0 and like all my boots, a good footbed ( I have pretty flat feet) and some basic boot fitting have made them comfortable enough to wear all day.

  9. MarkL September 22nd, 2018 11:16 am

    I realize this is an old article, but looking ahead to this season I would like to get a lighter boot to match with my light skis (Hannibal 94). Anyone have insight into how these compare to the F1 and the Fischer Travers? I would really like to see a review of the Travers. It’s tough to find much info on. Best I’ve seen is at

  10. Dabe September 23rd, 2018 5:56 am

    Mark, can you clarify your comment? Are you asking how the synchro compares to an F1? If so, they are in different weight classes and really are not apples/apples.

    Synchro is comparable to Maestrale in Scarpa’s line up and maybe Transalp in Fischer’s. “Free-touring”

    Conversely, Spitfire is direct competitor of F1/Traverse from Sportiva. “Touring”

    All that said, I have a pair of Spectres with Synchro tongues (see Lou’s post on the double power tongue) as well as a pair of Sportiva Sideral which is similar to the F1. The boots in this 1000-1200g class are very light, walk fantastic, and will easily drive your 94 waisted planks through everything short of giant slalom or hucking >10 footers. I’d say the speed limit is about 85km/h. If you need to go faster/bigger then “free-touring” boots are the place to go, as they bump the weight by only 200-300g and tilt the walk/ski ratio toward downhill performance.

  11. MarkL September 23rd, 2018 10:53 pm

    D’oh! I was thinking Sytron, but reading Synchro. My bad.

  12. Dabe September 24th, 2018 4:02 am

    Roger that Mark. You’re after a <1000g boot. An occasional race boot. Sounds like best bet is whichever of: Alien RS, Traverse, and Sytron offers best fit.

    Several consumer reviews of the Travers carbon and one for Sytron at

    Alien RS is reviewed well here on Wildsnow.

  13. Lou Dawson 2 September 24th, 2018 8:05 am

    Hi guys, we’re having connectivity problems here today so I’m not at my usual furious blogging pace. Noticed Dabe mentioned the Power Tongue post. Here is the universal resource locator:


  14. MarkL September 24th, 2018 11:59 pm

    Dabe – I am definitely not a racer, but I’m not a big high-speed hucker either. Sometimes I just want to cover some ground on pretty moderate terrain or with a pack, so I want to maximize the fact I have light BC skis. I used to tele and I have even thought about a NNNBC set-up, but I’d need different skis. Lighter boots like the Travers, F1, Sideral/Spitfire that ski decently is what I am looking for.

  15. Dabe September 25th, 2018 5:16 pm

    If F1 fits, go with F1. Best overall feature set. My $0.02.

  16. Max November 4th, 2018 5:56 am

    How does this one compare to Atomix Hawx XTD in terms of downhill performance?

  17. Kristian January 14th, 2019 8:45 pm

    Recently I was skiing steep deep heavy old snow on La Sportiva Vapor Floats and 2nd gen La Sportiva Black/Yellow Spectre 110 boots. Often felt like the boots were in walk mode and not enough support for those conditions. Thought that I had left stiff Lange Race like boots in the distant past. .

    Would the Synchros 125 help with fat skis and difficult snow, or more probable – do I suck at skiing difficult snow? 5′ 10″ 155 lbs

    All comments appreciated.

  18. Dabe January 15th, 2019 3:36 am

    I imagine getting a set of synchro tongues, a booster strap, and some tour wrap liners is cheaper than buying synchros. I have spectres with synchro tongues and think it’s great.

  19. boneyard January 15th, 2019 7:34 pm

    Kristian – My vapor floats also get squirrelly and hard to steer in difficult snow. I only ride them now on deep powder days (where they are awesome), and choose a different ski for other conditions. So maybe it’s not so much your boots…

  20. Kristian January 15th, 2019 8:04 pm

    Thanks Boneyard.

    I have to wonder about large surface area of broad high tips buried at speed in grabby snow. There may be an optimum algorithm of punch through it lower profile vs rise above it profile. In powder they are awesome!

    Picked up some Synchros. Beautifully made boots. Very stiff. Putting the double wrap liners into the high volume black/yellow Spectre feels about 115. Will test next against the newer yellow/blue Spectre and report back in a few days.

    Great suggestions Dabe!

  21. Kristian February 4th, 2019 12:57 pm

    Have skied the La Sportiva Synchos now. Here’s my experience:

    I was concerned that moving to a stiffer boot would result in shin bangs and getting thrown around on variable terrain.

    What I found was that these boots insist on my paying attention to what I am skiing and no day dreaming.

    They put author into authority. Much more precise control and power that i have not experienced since having Lange race alpine boots. They have a nice progressive flex. It’s important to pull the liners up at least 1 cm past the tongue when heat molding for comfort. And be sure to center the tongues.

    The boots only allow for a correct forward lean and skiing from your shins and ankles. There is no backwards flex for standing up. Getting into the backseat is literally not possible.

    They are almost a sort of passive exo skeleton for your lower body. The boots surprisingly saved me a great deal of energy expenditure over a day of downhill and I still felt fresh afterwards and the next day. In retrospect, I have been spending a lot of energy on propping myself up and staying in correct position. Kind of similar to being able to spend most of your time sitting on a full suspension mtn bike as opposed to spending the day standing.

    They excelled both at high speed groomer carving and highly variable funky tree skiing. They are relatively light weight and comfortable to walk in without unbuckling.

  22. Lou Dawson 2 February 4th, 2019 2:42 pm

    Hi Kristian, that’s pretty much my take as well. Thanks for chiming in! Lou

  23. Kristian March 5th, 2019 8:39 am

    Looked closely at and tried other 120+ flex boots, but the Synchro has much better comfortable support and progressive flex because of its tall design and tongue.

    Personally, I would be willing to order, pay, and wait for a more expensive similar design made with lighter weight materials like carbon, kevlar, dyneema, titanium, etc.

    La Sportiva is already doing this with their skimo race boots.

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