Having worked at a ski shop for many years, spending this winter in COlorado, and…well a design background and love for ID, I hope that I can offer some assistance.
There has been a number of attempts to do exactly what you are doing. The use of the buckle (in various forms) has been the most reliable because it is solid. The other attemts have used to the shell to maximize rigidity and the use of less exact closure systems. A good example of this, which has recently been revived, is the Raichle Flexon, which uses a cable which is tensioned when a knob is turned. Another system, rearentry (not a good design) involved a two piece shell, a front and rear, which had a single rachet in the rear (this was made by many companies in the late 80s to early 90s). There have been other hybrids, such as one made by salomon, which was between the traditional, cuff and boot design and the rear entry, and used an internal tensioning device with a knob to control the closure.
The closure system is corrolary witht he boot composition. That is to say, how the plastic components of the boot ar eassembled, and engineered.
Soft systems, such as the cable, or laces (yes boots used to have nylon laces, like shoes) have the propensity to loose tension when the boot is flexed, making it less tight and less safe. This is also a problem with the upper velcro strap on common boots, w problem solved by manufacturers such as powerstrap, who produce an elasticized solution, which can be over tensioned, and then gives enough when movement is needed.
In persuing this consider that there is a need for localized tightening conditions, i.e., the buckets serve different purposes, the bottom, to push the foot down, and the top, to hold the ankle and heal in place. This also allows for the boot to be adjusted to the wearer.
On fit. boot dont fit everyone, because the shell is hard. Different manufacturers work better with different feet. The system should not prohibit the shell form being modified, because in most cases, that will occur, it is part of regular boot fitting procedure; hydraulic presse, heat guns, etc. are used to make the shell fit your feet better.
The liner needs to be removable, it wears out faster than the shell and needs to be modified independently (oh ya, they get smelly if you leave them in the shell).
If you have any more questions, or want to bounce a design off of me, I would love to see it. architect@sol.dk
I dont know where you are located but, you should go to a small ski shop, someplace with character, adn ask the old guy that probably owns or runs it what he doesnt like about the boots he has seen for the last 50yrs. He probably wont have design advice for you, but you would know what quirky things have been unsucessful in the past, and what doesnt work.
These people are masters at the boot trade. They have a guy, whose name escapes me, who is a “pedorthist” that is considered one of the nations formost on Orthotics and custom boot fitting. He would be an invauble resource becuas ehe knows the boots, and the anatomics.
Lange has some of the best boots from a design perspective.
As to boot costs, they have been going up, the pair i’m on right now retail for $895, and its not inconceivable to spend >$1000 for a good boot and fit.
Peace
