We start covering anti-twist solutions for tech binding heels, and look what ends up on the front porch: Dynafit’s “original equipment manufacturer” (OEM) solution to the less than perfect anti-rotation of their Speed Radical binding heel. (In case you live in a bergschrund: Tech binding heels are usually designed with rotation to effect sideways safety release. This sometimes results in the heel unit rotating accidentally while in touring mode. Various solutions are directed at this problem, the best being hardware ‘stops’ that 100% block rotation.)
This add-on is part# 48870 Speed Radical Anti-Twist Device. Ostensibly available from customer service or through dealers. It looks simple, but is a little tricky to install properly. You have to use the included slightly longer screws, and be sure to flatten any “volcanoes” on your screw holes as the including washers need to sit perfectly flat on your ski. Clean everything well so no small bits of glue or dirt shim up the washers accidentally. Carefully epoxy and tighten screws that are going in for the second time as stripping screw threads in this situation is all too easy.
Weight of one Speed Radical Anti-Twist Device (including slightly more weight from longer screws): 16 grams.
Added height of heel unit above ski (thickness of washers/spacers): 1.0 millimeter
Could this device be built into the binding base? Yes, doing so would be beautiful. Let’s lay some odds on who will do it first, Dynafit or the after-market?
Check out the Maruelli Antitwist for Speed Radical, it works on the same concept but has interesting differences.