I started free-heel skiing on a pair of Freeride bindings in 2018, and I liked the concept of swapping the binding between multiple skis. To be honest, I only had one pair of skis, but I liked the IDEA of binding swapability. About a year ago, I became interested in the tech toe NTN bindings — first the Lynx (L) and then Medjo (M). After skiing both the Lynx and Meidjo, and drilling inserts into numerous skis I realized that even with threaded inserts the L and M bindings are not as easy to swap on add off as the Freeride. The Freeride binding slides onto a plate and is secured with two screws — simple enough for a 5-minute swap in the back of a car. To contrast, both tech bindings require at least partial disassembly and in case of M binding necessitates unscrewing the spring nuts and thus loosing the binding preload setting. In addition, the L and M tech bindings each use 6 or 10 screws respectively. My goal is a design that would allow easy binding swaps of L and M without binding disassembly and minimizing the number of screws I need to turn.
I want to share this idea here and perhaps get feed back from the more experienced skiers and tinkerers. Perhaps this idea was already developed by someone in the past unbeknownst to me. I should mention, I have seen shift plates and the like that save drilling many holes into the ski but my motivation is swapability without binding disassembly.
The design builds on the existing Rottefella pink rail used for the Freeride (I already had them available for experimentation). The binding is assembled on an aluminum (AL-7075) plate that snugly fits the Rottefella pink rail. This plate has M5-threaded holes spaced for the binding load-bearing mounting screws, and excludes the red bar and claw mechanism to save weight.
Binding Plate
The T-shaped front cutout allows for a replaceable plastic insert (PETG 3D print) to act as a front stop and can ultimately be used to adjust fore and aft binding position (not by much though, maybe 10 mm).
Front Insert
The rear of the aluminum binding plate is secured by another plastic piece (CF-PETG and PETG 3D prints) which secures the binding plate to the pink rail using 2x M5 bolts (these are the only bolts that need to be loosened to swap the binding). This rear insert also provides the mounting surface for the M red bar plate with appropriately spaced heatset stainless inserts. I built this rear section from two parts due to the anisotropic nature of 3D prints and print stability. I anticipated the black section (CF-PETG) is loaded in the fore/aft direction because it provides clamping onto the pink rail. Whereas the red section is a platform for M red-bar and takes much less stress.
Rear Insert
The binding is assembled on the aluminum binding plate, and the M red-bar guide is assembled on the rear insert. The whole plate-binding assembly slides onto the pink rail, and is clamped by the rear insert using the 2 bolts.
Assembly
This plate adds 12 mm of stack height to the binding, plus another 1-2 mm from the pink rail, making a total stack height increase of ~14 mm. The original Freeride heel plate works well, but I also made a similar rail-plate combo for heel plates which is can be moved from ski to ski.
I have yet to ski this as this was my spring/summer project, but I’ve carpet tested enough to convince myself it will not explode immediately and is safe for a real trial. With that said, I have only limited experience and would love to hear input, critiques or suggestions from anyone inclined to share.
Best,
Leon
