I think there's a lot of potential for spine support focused stiff and light boots with a truly adjustable forward flex profile to be engineered into touring boots in the future.
I have the Vulcan, and felt from the beginning that the forward flex feel could use some refinement. Been working on a simple rubber damper mod to make em ski better and have had great results for performance but dismal durability in skiin' em. It's been amazing to feel the boot flex like a rally car with long travel suspension absorbing macro and micro shocks/vibration and producing a super smooth and damp ride...until the rubber disintegrates and it's back to the stock system and a more jarring boot feel.
Here's what i propose...and it's something just a bit out of reach for my basement mod skillz/materials limits.
Employ something similar in concept to the Pierre Gignoux snowboard boot rear adjustable elastomer based piston to dial in spine supported forward flex characteristics. Have options of different elastomer durometer ratings for different skier weights/temp conditions, flex profile. I'd bet you could stack a few different pucks to produce a 'soft off the top, stiffer as you sink into the flex'...or, more linear profiles just based on how you arrange the softer and harder elastomer units on the piston.
Design the hardware so there is a 'hard stop' limit for rearward flex so that the only role the piston plays in affecting forward flex.
Advantages of this system is eliminates the need for an external tongue (save weight, eliminate fiddle fucking around factor), a carbon cuff could be designed stiff for desired efficient lateral power transfer and rear support but with the elastomer piston design, could easily accomodate prit near an infinite continually variable forward flex rating/stiffness so you could pare down a ski touring boot line to only one model for all. Also, i could envision the piston attachment to spine of cuff could be a bolt on design that could allow for easy adjustment of forward lean. Also, think about how temp affects boot flex feel. A lot times when skiing in warmer conditions, I think, yeah, boots feel nice, more supple flex/damper...then when it's cold they stiffen up to bricks. Have that adjustable forward flex engineered into the boot and dial it in to the conditions you face in the real world, and adjust in real time. Going for a mogul zipper line? Back off the tension and let that long stroke travel keep you in the balance point pocket. Wanna mach down some variable chop, crank it up a bit for more support for the bigger hits of lumps and bumps. Etc...

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