Switch Hitting Gear – Ramp Angle & Delta

Checking boot and binding lean, delta, ramp angles.

I got an email from Darryl a few days ago, asking if I knew what might be going on with his feeling that he was “going over the bars” on his Dynafit ski touring setup, while his alpine rig felt fine. Darryl is an expert and aggressive telemarker who also switches between a full-on alpine rig and a touring setup comprising tech bindings on a pair of fairly wide all-mountain skis. Since he lives near here, I emailed back with something like ,bring over all your skis and boots, we’ll see what’s going on with that.’

While Darryl related that perhaps he needed to mount his Dynafits on his skis in a different position, I suspected we were looking at the common situation of a skier trying to switch between two very different ramp (delta) angles and boot cuff lean angles. Some skiers can do this with aplomb, while others (myself included) do better if their gear is all set to similar angles that make the switch less abrupt.

So, we flopped Darryl’s planks on the kitchen counter, snapped boots in bindings, and measured.

Using my rig of a magnetic slope meter stuck on a tri-square, it was easy to see that his ramp angle (where your foot rests in the boot) was nearly flat with his alpine setup, while it was easily 5 degrees more than that with his Garmont Megaride & Dynafit rig (much due to the built-in ramp of the Dynafit binding). More, the Megaride has two forward cuff lean settings, and we concluded it was possible Darryl had mistakenly used the more extreme choice. Adding to the difficulty of matching boot feel, the Megaride has quite a bit of arch in the shell, while Darryl’s Tecnica alpine boots have a perfectly flat boot board.

Conclusion: Darryl’s two boots had enough difference in ergonomics to make switching uncomfortable and produce his “over the bars” non-brotherly situation. Solutions: Add a bit of ramp angle to the alpine rig by posting his heel with a shim under the boot board; subtract ramp from the Megaride by adding a shim under the forefoot; get custom footbeds for both boots so the arch is the same; mark Megaride with a Sharpie to indicate correct cuff lean position while latched. Both boots don’t have to be identical in ergonomics, but getting them close should make switching rigs an exercise in brotherly love rather than internecine warfare. If not, we’ll report back. More about ramp and delta angles, including numbers.