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TTS heel throws, alpine heels, and heel throw retainers

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  • TTS heel throws, alpine heels, and heel throw retainers

    I've been piling up used and discounted parts for a while, with plans of making a TTS rig for light backcountry use. I finally found a pair of used Voile Objective BC's and mounted them up for 2 short ski days before the pandemic hit. Now that I'm stuck in the house, I thought I'd take what I learned during the shakedown and improve it.

    Transitions are klunky with TTS. With a telemark heel, the best practice is to tuck the heel throw under a climbing bale. With an alpine heel (the tele-rando setup that I have), the best practice is to retain it with a bungee cord. This works fine for a big up and down, but gets tiresome in rolling terrain... the same terrain that inspired me to pick up the fishscaled Voiles.

    A heel throw with a 90 degree angle that holds the wire at the apex will give the most clearance from the boot when not in use, and lie as flat as possible. Both of these are essential when space is tight. Also, an alpine heel with a flat top lets the telemark heel throw lie flat. Heels with a big flip-down riser don't play nicely with a telemark heel throw, but flat heels that pivot 180 degrees for climbing mode can work.

    Solutions Considered

    1. Heel throw

    I looked at just about every telemark heel throw that exists, and played around with a bunch (Voile, OMG, G3, Rottefella). I even tried a Voile side throw heel, but that had a bunch of issues. The Bluebird Day Gear and Rottefella Riva Z heels are the closest to 90 degrees in shape. The Bluebird heel would need to be modified to hold the wire differently, and probably has clearance issues when resting on top of the boot heel. The Riva Z holds the wire in the right place, and has boot clearance issues.

    2. Retainer

    I tried the bungee cord method. It works, but is fiddly with gloves on, especially when rotating the alpine heel. I considered various spring-loaded clips. The thought struck me that a very strong, flat magnet could work really well.


    After trying a bunch of different configurations, I settled on the Rottefella Riva Z heel throw, modified to mate with a Scarpa F1 boot, and a neodymium ring magnet to retain the heel throw. The nice thing about this solution is the Riva Z heel throw uses a steel clip to retain the heel wire, unlike most which are plastic. That steel clip gives plenty of surface area for the magnet to hold tight. I can pick up the entire ski by the heel throw and magnet. Furthermore, using a magnet rather than a clip or bungee makes it easy to rotate the heel binding between touring, climbing, and alpine modes without fiddling with the heel throw.

    Heel throw:

    Click image for larger version  Name:	-hsHWBs1qTwmCLEMxRDvFTwmxfKsJvCiw8oAb_Z14h81y52udcj3W3h1oAjRxSLKR_YL96YWMHB1GUEa01VXcMbrNi0vjYBCju595FTifyAKmA16JVDKIBseY5we9oG9Tq4YDys2g6A=w600.jpg Views:	0 Size:	131.7 KB ID:	101564
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    Click image for larger version  Name:	RuRCHrc7fD9htf5ia7wFNjKpuDksVxHRaZM7Aqt3bBn9GopdIBhTsoHCF5LohVhJzq-zRCUTtMSib220-KjRjHSejICks9FzsEnwiOEdN7aPmXRJ6nyl-67x3V38-rmlsw7De7tU0OE=w600.jpg Views:	0 Size:	105.4 KB ID:	101565

    Heel throw retaining magnet:

    Click image for larger version  Name:	twrCkOnp3qetfKOb_QCUKTYvDuQXl7PoQ4tAupCMuQchHWQmOK4WBYNGlRHwHE2GTxRjZ6BA2iHRk42wnPMsGxSVXNzlO7_e3uVrOltfKaXmsM3kojoQopHlFju8I5lNUwgSU5evULE=w600.jpg Views:	0 Size:	102.4 KB ID:	101569
    Click image for larger version  Name:	_WIphDV6QAjFJ-cy1DUlVZRSl2s2LFgTyyAjvaF8L1zVt8p3-r3n0OYQIRC2kxlR1VhDNlZqZq8KHhbLErDf2KdyGMcOKvFejgq6tIgLVfHJZPqSXGaRjVOpMmkdO9-wVHcSWT4gBsU=w600.jpg Views:	0 Size:	120.6 KB ID:	101567
    Click image for larger version  Name:	OXTe7tEdPImf579qjjhzmGEsw2nJ9hoUadh-VDd6DPxDFHDuO4lI6RZiYu4xWhi2DN1BFLSN5X4aV7ZDlFNbKUS0GLJ21NetHWSgjHTQPummd30TvPcg-w_-b4daE067S8_vJ9Ji-h4=w600.jpg Views:	0 Size:	134.9 KB ID:	101566

    How it all works together during transitions:


    I haven't been able to get out on the snow, but in bench testing the transitions are as fast and easy as possible, and retention of the heel throw when in non-telemark mode is rock solid. The only move that requires stepping out is transitioning out of alpine mode. I have an idea on how to modify the heel piece to allow sliding it back with a pole (like the Meidjo alpine heel), but I'm not sure if it's worth it.

    I would love to 3D print a heel throw like this, rather than using bolts and epoxy. If anyone has pointers or would like to help, let me know!
    Attached Files
    Last edited by Dostie; 16 April 2020, 07:40 AM.

  • #2
    Damn, that is slick!! It looks like transitions would be incredibly easy, especially for us mitten-wearers.

    The (pre-modified) heel throw is the same as a Chili, right? Maybe I can sketch something up.

    Fully acknowledging that us gram-counting weight weenies are horrible horrible people, I have to ask: How much does the magnet weigh?


    • #3
      Thanks! Looks like the Chili heel throw is the same in profile. There are slight differences, but I think none are in the critical places. I did have to carve out a U shape in the lower section of the heel throw to clear the F1 ski/walk lever. I can draw what I mean and take some measurements if that would help.

      Is there any good free software for making these CAD sketches?

      Regarding weight, the gradations on my kitchen scale aren't that fine but the magnet weighs more than a penny and a little less than a nickel... so around 4g? It has 3kg of pulling force. It's surprisingly strong.


      • #4
        That video helped; I agree it's slick. When I was last using TTS, I just put the entire heel/cable connection in my pack. But, I only care about not being the slowest on the transition and there's often a snowboarder in my trio, so . . .


        • #5
          bobbytooslow I figured I was already waist deep, so why not get in over my head... I tried a few 3D modeling apps and settled on Fusion 360, which I really like after figuring it out.

          I found a model of the Rottefella heel, but it wasn't very accurate, so I rebuilt most of it using my own measurements. Then I applied the mods to make it work with the F1 boot... the tabs midway up should hit the heel around the ski/walk bar, the deep cup should clear the tour/walk lever, and the straight handle should give more clearance with the alpine heel.

          Click image for larger version

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          I'm sure my first attempt will have some clearance issues, but hopefully it will only take one round trip to get it right. Unfortunately a round trip is 2-3 weeks while I wait for Shapeways...


          • #6
            That looks great! This is by far the most sensible TTS/AT hybrid I've seen.

            The only thing I'd add to the heel throw would be a little pocket on the very top for the tip for your pole. And maybe make a version that replaces the Chili clamping plate with a plastic one and a broad flathead screw (which would provide the ferrous surface. Some companies (like BD) use a sheetmetal or wood screw right into the plastic, but I like modeling a little hex-shaped recess to capture a locknut.

            It looks like Shapeways lowered their MJF prices, which is great news for us. Did you try putting 2 throws in the same .STL (with a little connector) to see if it lessened the price at all vs 2 separate prints?


            • #7
              All good advice, thanks. Right now I'm waiting for my first print. My plan is to improve the boot interface with some contours, fix clearance issues, and beef up areas that feel weak/thin. But I need the part in my hand to do those. I already added a semi-hexagonal recess to hold the nut. Good idea on a wider tab for a pole tip. I will incorporate these into the next iteration. I'll also try doubling up on the model.

              I'll post back here when I have an update.


              • #8
                I finally 3D printed all the parts to get this binding setup in a usable state. The heel throw is modeled to follow the contours of the Scarpa F1/F3 heel while not interfering with the ski/walk lever and sitting clear of the boot when not being used for telemark. The magnet holds the heel throw out of the way when not in use.

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                The climbing riser mounts to the binding heel and is activated by spinning the heel piece 90 degrees. The high climbing bars are bent Voile risers and pivot on holes modeled into the low riser.

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                I wrote about the 3D printed bellows guard I made here.

                Here's a video showing the quick transitions between tour, climb, telemark, and alpine modes.

                All of the custom parts are available for others to print on Shapeways:
                Attached Files
                You may only view thumbnails in this gallery. This gallery has 4 photos.
                Last edited by jtb; 10 June 2020, 01:13 AM.


                • #9
                  Beautiful. I admire your design skills and your motivation to keep working on it thru the summer. I also pity the poor folks who'll have to try to hang with you on the skintrack!


                  • #10
                    Thanks! This binding setup on Voile BC's should make a versatile rig for the rolling terrain I typically ski.

                    My next summer project is to see if I can improve the release characteristics. I got a really good deal on a set of Trab TR-2's...


                    • #11
                      Nice job; very slick.

                      And I have the Voile Objective BC skis in a ridiculously short length, and that's awesome for summer adventures with your skis.