CAST SI&I Alpine Touring System

[Editor’s Note: We’ve got some very good news to report: CAST has met its goal on Kickstarter, and production of their SI&I binding is underway for this fall.

In more good news,  CAST will also be producing the Look, Rossignol, Head, Tyrolia, 4FRNT, Marker, Salomon and Atomic platforms, with production of the latter three being pushed up to September 2013 to further increase interest and sales in the SI&I System.

CAST will also be selling the SI&I and Boot Modification through their the website ( as well as through a select few shops, which they will be announcing at a later date. But Kickstarter is the only place to guarantee delivery of a SI&I system for this coming season.

And if you’ve read this far and still don’t know what we’re talking about, then you need to keep reading, because this is the only independent, actual review of the SI&I system out there.]


On March 13th, CAST went live with a Kickstarter program that you should know about.

CAST is a company started by Lars Chickering-Ayers and friends. The name comes from the term “a cast of hawks,” in honor of Ryan Hawks, a good friend of theirs and many others who passed away two years ago.

The CAST Kickstarter program is an effort to produce a new touring binding system.

The reason we care is that by any measure, Lars, his brother, Silas, and the CAST crew are great skiers and good guys. Plus, we think that CAST’s SI&I Alpine Touring System deserves to go to production. BLISTER reviewer Joe Augusten has been logging a lot of time on a CAST prototype, and, as he’ll explain, there is a lot to like about the system.

So watch this video, support this project however you can, and read Joe’s review to see if the CAST alpine touring system is right for you.]

CAST SI&I Alpine Touring System

Reviewer: 5’10”, 160 lbs.


  • Bindings: Look P18s & Dynafit Radical Toes, mounted to SI&I plates
  • Skis: 190cm Moment Bibby Pro
  • Boots: Lange RS 130

Test Locations: Alta Ski Area, Solitude, Little Cottonwood Backcountry, Tahoe Backcountry, Mt. Rose, Alpine Meadow, Squaw Valley.

Days Skied: 15 Tour, 40 Inbounds


To get an idea of what I look for in a backcountry touring binding setup, check out my introduction to the novel I wrote about the MFD Alltime a year and a half ago.

In short, I’m married to the Rossignol FKS / Look P18 alpine binding, and I don’t want to go downhill on anything else.

My monogamous relationship with the FKS is founded upon the amount of elastic travel that the FKS provides, and its outstanding release and retention characteristics. In short, they retain when they should, release when they should, and reduce the amount of force transferred to the knees—exactly what you want from a binding.

(For more on elastic travel and release values, see BLISTER’s Dyanfit Beast 16 review.)

In addition, I also want to tour in my Lange RS130s with ZipFit liners, two booster straps, and boot heaters. You know, since I’m all about saving weight.

When I first heard about the CAST system, it was a day or two after I had just purchased my MFDs. My immediate reaction was to send the MFDs back. The CAST system was it, they nailed it—assuming, of course, that they could actually get it produced….

But if Lars Chickering-Ayers was designing a touring binding system, I wanted to be on it.

I first met Lars in 2005 at a Crested Butte comp, about to drop in on Slot Rocks for run one. Lars had moved west just a couple of days earlier from Vermont and was new to the comp scene, as was I. Next thing I knew, he was sitting in first place by half a dozen points. As everyone well knows, that was just the beginning.

Initial Impressions of the SI&I System

For me, the idea of touring up on a Dynafit toe, swapping out toe pieces at the top, and skiing down on my FKS directly attached to the ski really can’t be beat.

Two and a half years ago, I had just convinced myself that the MFD should be a better touring system than anything out there (which I confirmed in my review). Then CAST came, and this system looked as if it would trump the MFD on many fronts. To say the least, I was very excited. After talking to Lars about proto testing the first batch, and waiting for them to go to production on a small run, I was finally on the system by the spring of 2012.

CAST Binding Toe Pieces, Blister Gear Review
Original SI&I Prototype Tested

(Note: all photos from here on out will be CAST stock photos of final P18 system.)

This review will focus on the third prototype of the SI&I system that I have been skiing, which was the last version built before they started to use a CNC machine to manufacture the plates. They have subsequently tested four new iterations in order to refine the design. In general, my assumption is that the final run will in every way be an improvement over my early prototypes.

Lars and his team have not looked to cut corners. Their goal from the get-go was to develop the best, most bomber touring system on the market. The system has been through a lot of Finite Element Design and will continue to see more, with strength and pullout testing at the University of Vermont labs this spring and summer.

There will be some questions left unanswered, as most details have been honed and improved, but what I will try and cover here is how well this system tours, switches over, and skis. In addition, I will address some of the more common questions or concerns about the system.


29 comments on “CAST SI&I Alpine Touring System”

  1. Nice review, thanks!

    But one thing is wrong: it makes a huge difference if you have more weight on moving parts or in your backpack. I wouldn’t change the system, it seems just fine. The difference is the acceleration needed on moving parts: the heelpiece of the binding has to be accelerated each step if it is on the ski by your foot. If it’s in the backpack that acceleration is not needed because the upper body doesn’t have to be moved like that. Consider a bicycle wheel and attach some weight to it, the farer away from the axis, the stronger you have to pedal – same with boots, bindings and skis, they are moving to get you up. The torso itself doesn’t move, it is moved. Just go running with you skiing boots on and compare it to having them in you backpack and notice which one costs more of youre legs energy.

    sorry for my lacking english skills

    • Hi, Burny – I agree with your point. What I was focusing on was that removing the weight of the binding from the heel of the boot during touring is the major benefit, and that is more important than reducing weight on the ski.

      Not only are you accelerating that extra weight on the heel, but you are also pivoting and lifting it up and down with every step. The ski stays at a consistent height compared to your torso, and is moved the same number of vertical feet. Since nobody’s going to use this system for rando racing, I was emphasizing that this a bomber alpine system that also tours incredibly well compared to anything but a full tech setup. Some people will want that removable heel for the reason you mention, I’m just not one of them.

      But you make a great point, we will revise and try to clarify. Thanks for reading and for the comment.

      • Yes, that’s totally correct – in fact that is one of the major benefits of the dynafit invention. It’s great to see that idea in combination with a true alpine binding. The system Silas and his brother came up with is so simple, yet it seems the right path.

  2. Joe, you downplayed having a removable heel piece but the reason I would be very interested in that option would be to have the same flexibility as the MFD system and swapping to other skis. For $75 you can get the mounts on another set of skis and just swap the MFD plate around on different sets of skis (assuming brake width is adequate for the various sets of skis). Without the removable heel piece with the CAST system, you need to own/buy another set of bindings for another set of skis you want to make compatible. Am I missing something in my logic? MFD is a very cost effective way of making multiple skis AT compatible, especially when I paid just $140 for a new MFD system.

    By the way, love all the write ups. Thanks.

    • Slide,

      I mentioned this briefly at the end of the section discussing the removable heel. To me, I’d rather deal with binding freedom inserts on he heel (half as many as the total binding, not too bad) and not have the added weight skiing, or the manufacturing cost. You are still able to swap all bindings between skis, although now it will take 5 minutes versus one. It’s all a personal preference. I completely understand wanting the swappable heel plates, but they aren’t for me personally.

      The added 5 minutes of switch over time in the garage will be saved by the quicker skin to the top when compared to the MFD.

      And the swappable heel plates will be a reality some day, but this project started off to make a bomber touring setup, which they did. Once we fund that, who knows what CAST will come up with next, but I guarantee that swappable heels is on the list.

    • Rob,

      Going up you’ll be on just the dynafit toe piece, so that would work fine. Going down, you’d have to check the compatibility of the boot with your current alpine binding setup. Personally I feel you need a sliding afd to work with vibram soles, but some people have made them work by modifying the toe piece or the boot sole.


      • For the latest on AT/technical boot compatibility with alpine (DIN) bindings – see Backpacker Magazine, Sept 2014 (pg 46). Engineers at Uni Of Washington/Seattle tested 120 combos of AT boots & alpine bindings for their release capabilities. And found that very few combos will release correctly. Even if the boot fits into your alpine binding, you’ll very likely never be sure it’ll release when or how it should. And you may even be damaging those bindings. Hmmmmm…

  3. I H8 those dorks behind me who freely mooch off my trail breaking efforts and then have the unmitgated audacity to poach my pow line. (there’s got to me a snowmenclature term for that!)

  4. Quick question that I have due to looking at the above pictures.

    One of the benefits of the Pivot system, is that your heel can “pivot” out when the binding releases. However, looking at the pictures the, side of the risers when locked down look as if they would prevent this from happening as the boot heel would catch on them.

    This seems a pretty big problem or is it just the angle the pictures are taken from??


    • Steven,

      I don’t have the updated system yet (should in a few weeks here and will update). But I believe it is the angle of the picture. I can’t imagine that would be an issue. Although I do see what you are looking at.

      I’ll update when I receive the new setup.


      • Thanks.

        Yea, it would be very odd for that to be the case, but would still be good to have an affirmative answer.

        Enjoy when it arrives! I’m jealous!

  5. Hello,

    I’m thinking of getting a Cast setup and had an auxiliary question. What’s your opinion on riding bindings at the very lowest end of its DIN setting (8 in the case of the CAST-compatible FKS18)?


    • Vince,

      There are a couple good write ups on the site in the Bindings 101 and 201. These discuss this exact question.

      Personally, if you are going to rock a p18 on 8, I would be inclined to go with a p14 to save weight. The toe is a slightly different design, but you still get all the benefits of the pivot heel.

      If you aren’t concerned about weight, there is no reason you can’t run a p18 at the low DIN setting.


      • There exists such a thing as a single-pivot toe in a 6-15 DIN: Rossi FKS155. Once I get the new (apparently only available in Canada, suckers :P) WTR compatible AFDs for them (just to be clear, only for single-pivot toes, no such thing for 14 DIN toes), and some wide brakes, I’ll have a pretty sweet setup for my Kuros. Oh, and save up $275USD at a craptastic exchange, guess I shouldn’t have mocked y’all.

        Joe, couldn’t agree more about single-pivot Look/Rossi, and about sliding AFDs. Sounds like you value your knee ligaments as much as I do.

        All this effort to be able to use one set of boots for alpine and touring, which is key when you gotta fly to the goods.


  6. Nice write up on the CAST system. Quick question. Does the dynafit crampons work with the Cast plates? Looks like it should fit no problem but would be nice to get a confirmation that they don’t interfere.

    Slightly off topic but do you know if a BD Factor 130 w/AT sole fits in a Look P14 toe piece. Deciding between them or the Salomon STH2’s to pair with a CAST setup.

    Thanks in advance,


  7. I imagine you Joe or some of the other guys at Blister will have put a bunch of more days on this system this season. It would be really good for another update, especially as I read they have dropped the weight down to 180g per ski.

    • Considering the snow in Tahoe this year…unfortunately I haven’t put a “bunch more” days on these. However, I’ve put enough on them that I have stopped even looking at what else is coming down the pipe line in terms of AT setups. IMO, there isn’t a design that compares if you’re looking for a system that is alpine oriented. It makes almost no compromises on that end, while being very efficient on the touring end when comparing to a Duke, etc. I always joke with my buddies when I’m switching over about how “inconvenient” the system is to transfer over. Some folks think/say it’s a pain. But it’s only the folks that have never used them that have those comments. They are awesome, on all fronts, period.

    • …or any frame AT system for that matter. Brilliant thought. TotAlly blows away the foregoing discussion. Well played, sir!

  8. Hey all. I realize this is an old thread but the Blister site is pretty active and generally has helpful comments so I figured I would post this here.

    I have been using (and loving) the CAST SI&I setup since their kickstarter campaign. It’s totally bomber on the downhill and tours great going uphill with only a minor delay when switching over (seems comparable to the swap time of my old dukes, mostly because you have to take your boot out of the binding during the changeover). I’ve ran into a discouraging issue this fall, however, when trying to use a pair of Scarpa Freedom RS boots. It seems the rockered “Mountain Plus” sole (the ones with the tech toe piece) will not work with Look Pivot toe pieces (too low of a stand height, around 20mm). This means the incredibly popular Scarpa Freedom boots can’t be used with the SI&I system unless one was to modify the “Piste” (DIN) sole to have a tech toe.

    Does anyone have experience with this issue? It’s a pity they aren’t compatible as they are both awesome products.

  9. One year after the last guy…but I’ll give it a shot.

    The last two seasons I have toured with my snowshoe/snowboarder friends, key is we ALL use snowshoes. Needless to say, this is probably the most annoying and heaviest way to tour, as I was putting my alpine boots and my skis on my back. This year, I refuse to keep doing this and would like to purchase a touring setup. However I don’t like the idea of sacrificing a pair of skis to touring since I will only do it about 5-10 times a season.

    I am still planning on getting a pair of WTR boots, potentially Salomon’s, and have been considering the Marker Kingpin. But this means on ski trips I still have to bring two pairs of skis. I like the Cast system because you get the best of both worlds on one pair of skis, as well as not sacrificing the performance of the alpine binding inbounds or in rough out of bounds conditions. Am considering this system with the Look Pivot 14s. Are the WTR AFD plates needed for the 14s or only the 18s? Or was it only for Scarpa?

    I have no previous experience on pin bindings, but the idea of them going downhill seems crazy. How would you rate this system compared to whats out there for the 16-17 season?

    • Hi Elise:

      I know this is a late reply and you’ve probably already purchased your bindings and have been skiing on them all season, but here are answers to your questions in case it helps you or others:

      Boot Compatibility:
      Keep in mind that WTR is a design specific to Lange and Rossignol boots, so technically WTR AFD plates are only certified to work with Lange or Rossi boots with WTR soles. That said, they might work with other rockered soled boots.

      If you buy rockered soled boots or WTR boots, you will need one of the following bindings:
      1) New Look Pivot 14 Dual WTR bindings (switchable AFD between WTR and DIN boot soles)
      2) Look Pivot 18’s with aftermarket WTR AFD plates (CAST sells these replacement plates, they seem to be rather rare but CAST must have bought up a stockpile directly from Look)
      3) Choose another binding with adjustable height AFD, Marker and Salomon both make adjustable height AFD bindings and CAST made systems for both brands of binding.

      If you choose to buy non-rockered boots and do a CAST tech sole conversion:
      1)Use old-school solid plastic soled boots and DIN standard AFD’s on Look Pivot 14 or Pivot 18.

      I sent CAST a pair of solid-plastic soled boots from 2008 and they did a great job on my boot sole conversion. If you want to put tech inserts on a different boot (not solid-plastic soled) you will need to contact Lars at CAST and find out if he can convert it for you. Since Lars’ personal boots in his videos are race boots with solid plastic soles, I suspect that the solid sole conversion systems have gotten plenty of R&D.

      How I would rate these bindings compared to other AT options this season:
      All told, the CAST system is more expensive than most of the other burly AT binding options, but it is the only system that does not sacrifice performance anywhere (climbing efficiency or skiing power and security). I’m sure other people on the internet will argue, but those people probably think that Marker Kingpins (or insert favorite tech binding here) release and retain their boot just as well as Look Pivot 18’s. I don’t think so. If you want to be able to ski resort and backcountry terrain on the same solid setup, without missing a beat or ever second-guessing your equipment, CAST is the best option. If you can afford to have a quiver of skis, boots and bindings and don’t mind changing from one setup to the other from resort to backcountry to optimize for skiing vs climbing depending on the day then there are other viable options out there.

      I hope this helps! I have been skiing the resorts on my Look Pivot 18 CAST system all winter and they work flawlessly. I can charge hard in my race boots or my softer CAST converted tech boots (same BSL, DIN standard soles) without making any adjustments to my bindings or skiing style.

      I have only used the walk-mode of the bindings 3 days this season, and those were mostly shake-down runs for my new toys. The changeover was a little fiddly if I got snow in the interface, but I have since rubbed some Holmenkol yellow ski wax on the interface to keep snow from sticking and I’m planning to do some spring tours in the coming months to try them more. I love the confidence of clicking into my Look Pivots on the changeover, I have always skied on race bindings and I know when they’ll stay on or come off. With Look Pivots I can run a nice safe-for-my-knees DIN of 10 without having pre-release problems.



  10. I am still using these in 2024.. you could get these with a lot of different bindings with the originals. I am still running marker squires and K2 pinnacle-mind bender boots. The only time I had a pre release was when I skied into a stream. Like them a lot.

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