Sportiva Synchro Double Power Tongue Swapology

Post by blogger | March 13, 2018      

(This post sponsored by our publishing partner Cripple Creek Backcountry. We hear they are into tongue swapping.)

Left to right. Original Spectre tongue makes and effort, with bellows hinge, but still obstructs natural touring stride. Sportive two piece power tongue solves the problem. Installed on Spectre. Install hints: Tongue mount can be loosened just enough to pop tongues in and out, but in doing so you might drop a T-nut from the inside. If that happens stick the T-nut up with a square of duct tape so it's easy to re-insert screw.

Left to right. Original Spectre tongue makes an effort at walking freedom, with bellows hinge, but still obstructs natural touring stride. Sportiva two piece ‘Double Power’ tongue solves the problem, installed on Spectre. Install hints: Tongue mount can be loosened just enough to pop tongues in and out, but in doing so you might drop a T-nut from the inside. If that happens stick the T-nut up with a square of duct tape so it’s easy to re-insert screw.

Sorry kids, this isn’t a kissing howto. You can find that over at Cosmo. Meanwhile, La Sportiva’s Double Power Tongue is one of the best ski touring boot innovations in years (see Synchro review for more details). This cultural event is not quite on the level of when cavemen went from bare feet to sandal, but close. In case you’ve been out of touch, perhaps living in a crevasse on the Kahiltna, the idea is simple. Read on.

Regular “tongue” style boot shells have trouble allowing adequately free forward motion in touring mode, due to the shell tongue obstructing forward movement of your shin. Providing some sort of hinge in the tongue is the usual solution, but doing so compromises downhill stiffness. Sportiva’s two piece tongue is easy hinged for touring (though we’d like it to be totally free hinged) , and stiffens up when you buckle down by virtue of a separate smaller-stiffer tongue the keys into the underlying full tongue. (Other companies have tried this sort of thing over the years, but in our opinion never this effectively). Sportiva’s solution works, albeit you need take care down to align the two tongues when buckling. You get used to it, and it’s worth it.

Secret sauce, the darker part matches up with  the orange cutout, locking together when the boot is buckled.

Secret sauce, the darker part matches up with the orange cutout, locking together when the boot is buckled. Getting the parts to mate during buckling is easy, a bit tougher configuring for walking as a buckle that’s too tight will lock the parts together.

Of course you mod-happy readers of have already asked: “Swap this to the earlier Spectre models?” Sure. And more.

Orange on yellow? Hey, it's La Sportiva, need we say more?

Orange on yellow? Hey, it’s La Sportiva, need we say more?

For grins, I swapped a Sportiva tongue to a Scott Cosmos 3, am pleased with the results.

For grins, I swapped a Sportiva tongue to a Scott Cosmos 3, am pleased with the results. Problem: the tongue is sold WITHOUT the hing-holder bracket the screws go through. That part might be available as well, I got mine from an old pair of original Spectres we have here for parts.

Sportiva bracket on Scott Cosmos.

Sportiva bracket on Scott Cosmos. The holes nearly line up, I egged them out using a roto-cut bit on rotary grinder.

Tape backing for T-nuts.

This type of project requires three hands, if necessary back the T-nuts with a square of tape so they don’t fall into the boot shell as you attempt to thread screws.

Good result.

Good result.

The info you need for ordering, probably through a dealer.

Some of the info you need for ordering, probably through a dealer. Sportiva ITEM NUMBER is 49H in their catalog.


Please Enjoy A Few Suggested WildSnow Posts


24 Responses to “Sportiva Synchro Double Power Tongue Swapology”

  1. Bob March 13th, 2018 10:34 am

    It looks like the hinge holder lines up perfectly with the big toe hole on the Cosmos 3 and only the pinky toe hole needed to be egged out. Correct? I have the new tongues on some old Spectre and they are indeed very close to the original Spectre tongues in terms of touring. Want to switch them to my Cosmos 3.

  2. Lou Dawson 2 March 13th, 2018 11:52 am

    Hi Bob, I egged out both holes, it was no big deal, the T-nuts are much larger than even the egged out holes. Original tongue would swap right back on. It’s a good mod for the Cosmos. Getting the rivets out of the Cosmos is a bit of a chore, to avoid heat and grinding damage. They can be replaced with T-nuts if necessary.

    Another nice feature of doing this to Cosmos is you end up with hinged tongue, easier entry-exit.


  3. Jim March 13th, 2018 12:35 pm

    Is there any significant difference in stiffness with this mod to a Spectre?

  4. Lou Dawson 2 March 13th, 2018 12:42 pm

    Stiffer in downhill mode, looser in uphill, both improved. Lou

  5. Mike Henrick March 13th, 2018 2:55 pm

    Nice! Works on a Cosmos – how about a Backland?

  6. Skis_the_trees March 13th, 2018 3:29 pm

    Looks awesome. Will this work with the Sideral 2.0? Unclear if the upper cuff/buckle on the Sideral would lock down the tongue hinge.

  7. MarkL March 14th, 2018 12:14 am

    Are the holes the same on a Cosmos II?

  8. Dabe March 14th, 2018 4:35 am

    Lou if those spectres are a 27.5, would you consider selling them?

  9. Lou Dawson 2 March 14th, 2018 11:28 am

    Dabe, we don’t sell much gear, quite a bit of it is on loan or else ends up too worn out or customized, I emailed you to discuss further, perhaps we can offer some advice. Lou

  10. Dabe March 14th, 2018 1:56 pm

    Thanks Lou! I replied there but will also second the_teees query, do you think sideral or spitfire buckles will work with synchro tongue?

  11. Kip March 16th, 2018 6:12 am

    Thirded on the query whether this will work on a sidral 2.0. My main concern is that the two parts wouldn’t detach with the top buckel undone as there is not much slack space.

  12. Lou Dawson 2 March 16th, 2018 7:35 am

    I think it might work, I can experiment today. I’ll make a point of doing so. Give me a few hours. Lou

  13. Dabe March 17th, 2018 7:00 pm

    I asked Sportiva warranty dept as I recently broke a rear cuff on my sideral (which they have felt with in A+ fashion – shipped a new pin and cuff with instructions on how to repair). The response was that it would not work:

    “The Synchro tongue will not fit on a Sideral.
    The attachment point is oriented in a slightly different direction, and will not line up with the rest of the boot.”

    But I think like Lou’s cosmos, you could get the alignment right if you made new or modified old holes.

  14. Kip March 19th, 2018 8:46 am

    Thanks for the info Dabe. I just had a look at the Sideral 2.0 attachment point and notice that it dosen’t have the same metal peice as the specter/syncro and has 3 mounting points. So despite the Sideral tounge looking the same as the blue one in the first picture it must actualy be different. The difficulty of swapping would therefore be simlar to the Cosmos. For me this wouldn’t be worth risking as they are my only boots and it might not work out….

  15. Skis_the_trees March 20th, 2018 7:51 pm

    Lou – were you able to check if it would work on the Sideral 2.0 (despite the response above, thx kip).

  16. Lou Dawson 2 March 21st, 2018 6:15 am

    Hi Skis, yeah, I want to check this for myself. Got delayed, I think I can get to it today. Thanks for asking. ‘best, Lou

  17. Lou Dawson 2 March 21st, 2018 12:25 pm

    Ok, SkisTrees, I have some Sportiva Sideral boots here to play around with, but I can’t mod them. It looks like you could widen the hinge slot in front end of the Power Tongue by a total of 8 mm (4 each side) and you could snap it into the same fitting-hinge as exists on Sideral. The original Sideral tongue can probably be removed with some heating and prying, but might require removing the 3 rivets holding the tongue hinge fitting and replacing them with T-nuts.

    Also, as mentioned above, I’m not sure the buckles would fall in the correct places on the Power Tongue.

    In all, possible but probably not worth the effort and expense.

  18. Dabe July 20th, 2018 4:18 pm

    I’m just about to purchase my 2.0’s to try this on so was revisiting post and noticed that flashy yellow rear spoiler! Do you have a part number for that Lou?

  19. Lou Dawson 2 July 20th, 2018 6:33 pm

    Dabe, those came with the boots, you’d have to ask Sportiva if they’re sold under their own SKU. Lou

  20. Rossco October 26th, 2018 2:32 pm

    Is there anything different (sans liner) between the modified spectare and the synchro? It seems like they are the same shell after this?

  21. Lou Dawson 2 October 27th, 2018 7:23 am

    Hi Rossco, my recollection is the Synchro has a few changes to the mold that make it stiffer, possibly a different plastic formulation, and some work to change the fit here and there. I also recall changes to lean lock. I would not call it the “same shell” though I’d call it quite similar. Bottom line is if you like the fit and overall flex of the Spectre, and do this tongue swap, you’ve got nothing to lose and could avoid buying a new pair of boots. But if you want a bit more from your boots, consider overall upgrading. Ski touring boots these days are in a time of rapid development/improvement, thus always good to look at new options, especially if you can find something on sale. Interestingly, contrary to the incessant drumming of the PR stories, I feel ski touring bindings are in a time of static development, with machines such as Shift taking attention away from the fact that what most people will use for actual human-powered skiing are virtually the same thing they were 20 years ago. Not that that’s bad (the classic tech binding is still genius), but point being the boots are where the fun is these days.

  22. Cory January 27th, 2019 2:00 pm

    Were there significant uphill/downhill performance improvements doing this swap on the cosmos iii?

  23. Lou Dawson 2 January 28th, 2019 5:57 am

    Cory, it reduces the effect of the tongue blocking forward movement of your shin during the uphill. No real change on the downhill, as the standard Cosmos tongue is already moderatly stiff. Lou

  24. Cory January 28th, 2019 3:11 pm

    Does the additional forward range put the Cosmos III close to the Spectre/Synchro in regard to mobility? I would like like to pickup the Cosmos III because the fit is great but the ROM is a concern as i’m coming from the Spectre 1 and enjoy the freedom of movement it provides in the skin track and booting.

Anti-Spam Quiz:

While you can subscribe to comment notification by checking the box above, you must leave a brief comment to do so, which records your email and requires you to use our anti-spam challange. If you don't like leaving substantive comments that's fine, just leave a simple comment that says something like "thanks, subscribed" with a made-up name. Check the comment subscription checkbox BEFORE you submit. NOTE: BY SUBSCRIBING TO COMMENTS YOU GIVE US PERMISSION TO STORE YOUR EMAIL ADDRESS INDEFINITLY. YOU MAY REQUEST REMOVAL AND WE WILL REMOVE YOUR EMAIL ADDRESS WITHIN 72 HOURS. To request removal of personal information, please contact us using the comment link in our site menu.
If you need an emoticon for a comment just copy/paste off the following list, or use text code you might be familiar with.

:D    :-)    :(    :lol:    :x    :P    :oops:    :cry:    :evil:    :twisted:    :roll:    :wink:    :!:    :?:    :idea:    :arrow:   
Due to comment spam we moderate most comments. Please do not submit your comment twice -- it will appear shortly after approval. Comments with one or more links in the text may be held in moderation, for spam prevention. If you'd like to publish a photo in a comment, contact us. Guidelines: Be civil, no personal attacks, avoid vulgarity and profanity.

  Your Comments

  Recent Posts

Facebook Twitter Email Instagram Youtube


  • Blogroll & Links

  • Welcome to Louis (Lou) Dawson's backcountry skiing information & opinion website. Lou's passion for the past 50 years has been alpinism, climbing, mountaineering and skiing -- along with all manner of outdoor recreation. He has authored numerous books and articles about ski touring and is well known as the first person to ski down all 54 of Colorado's 14,000-foot peaks, otherwise known as the Fourteeners! Books and free ski touring news and information here.

    All material on this website is copyrighted, the name WildSnow is trademarked, permission required for reproduction (electronic or otherwise) and display on other websites. PLEASE SEE OUR COPYRIGHT and TRADEMARK INFORMATION.

    We include "affiliate sales" links with most of our blog posts. This means we receive a percentage of a sale if you click over from our site (at no cost to you). None of our affiliate commission links are direct relationships with specific gear companies or shopping carts, instead we remain removed by using a third party who manages all our affiliate sales and relationships. We also sell display "banner" advertising, in this case our relationships are closer to the companies who advertise, but our display advertising income is carefully separated financially and editorially from our blog content, over which we always maintain 100% editorial control -- we make this clear during every advertising deal we work out. Please also notice we do the occasional "sponsored" post, these are under similar financial arrangements as our banner advertising, only the banner or other type of reference to a company are included in the blog post, simply to show they provided financial support to and provide them with advertising in return. Unlike most other "sponsored content" you find on the internet, our sponsored posts are entirely under our editorial control and created by WildSnow specific writers.See our full disclosures here.

    Backcountry skiing is dangerous. You may be killed or severely injured if you do any form of ski mountaineering, skimo randonnee and randonnée skiing. The information and news on this website is intended only as general information. Due to human error and passing time, the information, text and images contained within this website may be inaccurate, false, or out-of-date. By using, reading or viewing the information provided on this website, you agree to absolve the owners of Wild Snow as well as content contributors of any liability for injuries or losses incurred while using such information. Furthermore, you agree to use any of this website's information, maps, photos, or binding mounting instructions templates at your own risk, and waive Wild Snow owners and contributors of liability for use of said items for ski touring or any other use.

    Switch To Mobile Version