Since Simon Zachhuber is a on tight schedule, I am providing my preliminary observations on the FreeMotion ski boot.

A few days ago, Simon sent a copy of what appears to be a patent application for the FreeMotion ski boot. The application appears to have been received by the patent office on September 1, 2010.coverSince I cannot read much German, I would appreciate it if anyone who reads German and who notes errors in my interpretation to please bring them to my attention.

The initial promotional activity for the Freemotion ski boot seems to have occurred between December 28, 2011 and January 25-26, 2012 with videos posted on YouTube. In studying the videos at 0.5 and 0.25 speeds, the skiers demonstrating the FreeMotion ski boot seem to lack fluidity.

In studying the flexion of the Freemotion ski boot, as demonstrated between 0:58 seconds and 1:10 seconds (Perfekte Passform – Perfect Fit) into the video, Freemotion Skischuh Ein & Austieg, it appears that the resistance to forward shank movement is introduced too early and rises too steeply.

Patent Figure 2, below, provides some insights that might explain why the skiers demonstrating the FreeMotion ski boot appear to lack fluidity.

The mechanism that is most likely the primary subject of the patent application is the Flex Spring (annotated in red) that links the shell lower to the rear Exo Cuff. The retention mechanism for the foot appears to be a diagonal band drawn together by cords that exit at the top of the forward aspect of the tongue.


Figure 8, below, shows the draw cords (28, 29) that pull the diagonal bands together. This mechanism draws the heel of the user’s foot into the rear of the lower shell.


Summary of my Observations

  • The primary innovation appears to be a U-shaped spring that opposes forward rotation of the Exo Cuff thus transferring force to the front of the shell lower.
  • There does not appear to be any hard limit to the rearward movement of the shank of the skier.
  • There does not appear to be a forward lean (forward angle) adjustment for the exo cuff.
  • There does not appear to be any means to adjust the resistance curve of the spring.
  • If the Heel Retention Mechanism is securely tensioned, it is likely to obstruct the glide path of the distal tibia on the talus. This can cause the center of force on the shank at the buckle secured to the Exo Cuff to rapidly drop down the shank.

As observed in the videos:

  • The resistance to forward movement of the shank provided by the spring mechanism appears to be introduced too early and rises too quickly.

If Simon or others with an interest in the FreeMotion ski boot wish to comment on my preliminary observations, I will respond and try to provide some suggestions for solutions in a follow up post.