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One view of the bootfitting mystery? Long

post #1 of 25
Thread Starter 
This thread has gotten me going back over some of the stuff I saved from several years ago. They are quotes from others, one in particular. Since there has been some interest I thought I would quote a few parargraphs that might be of interest.

“Studies done at the University of Calgary’s Human Performance Laboratory have conclusively shown that our feet function best when bare. I did experimental research on balance in skiing back in 1991 with an instrumented device that replaced the ski boot. The device allowed the parameters of constraint applied to the foot and leg to be varied in a systematic manner and the effects on balance measured during typical ski maneuvers. The results were very interesting. When an environment conducive to the natural processes of balance was created all good skiers (including former Olympians) used essentially the same balance mechanisms. Even more interesting was that novice skiers started to use the very same mechanisms after only a few short runs -- with no coaching!”

“The first thing I do with new boots is to try and get a feel for the components. I try the liners on outside the shells to see how they fit my feet.

Next I rehearse my stance on a flat hard surface then stand in the bare shells with them placed hip width apart and parallel as if I were on my skis. I want to get a feel for how the boot affects my stance, whether the side cant is neutral on the sides of my legs and where the forward lean is at for my stance.

Next I want to try and figure out the net ramp angle. This is the ramp angle of the boot board combined with the ramp angle of the binding. The best way to check this is to put your boots on your skis and then stand in the bare shells.

When standing on a flat hard surface CoM is only slightly ahead of your ankle. This is efficient for walking because as CoM moves forward it has to cause the heel to lift. It is also more efficient for quiet standing. But for skiing CoM needs to be farther forward. So the base of the boot needs to be inclined forward. You can actually calculate the ideal amount mathematically by comparing the length of the foot to the length of the limb supporting CoM. It is about the same for everyone and it is around 3 degrees.

If the net ramp angle is too great CoM would have to go beyond the balls of the feet. This will disturb the critical angles of the ankle and knee required for eccentric contraction. I usually have to raise the forefoot even with my long foot. I do this by shimming the forefoot of the footbed or bootboard with some sort of gasket material or 1/16 in thick plastic shims. I also use a material that is like a plastic cement caled Raycrete to build up the front of the boot board.

I try and get the ramp angle sorted out before I do much with the tongues.”


“Make sure that your inside ankle bone and the small bone below and in front of the ankle bone has clearance. Do this in the bare shell.

If you have a flat, fleshy foot the inner aspect between the ankle and ball of the foot will often hang up on the shell. You will usually not feel this because the shell pressure is distributed over a large area. But it can keep your foot from sitting properly in the boot base. If you think you may have a problem let me know. “

“David: you recommend what I think is fairly firm foam over the instep. Why doesn't this block supination?”
“David: When you change ramp angle, why do you prefer to raise the boot board toe rather than lower the heel?”


David said
It does block supination to a large extent. I want to retain some of the loading in the arches of the foot. I will expand on this later.

If I want to lower the ramp angle I can either lower the heel or raise the forefoot.

The problem with lowering the heel is that it involves grinding down the top of the boot board surface. If the foot has a low instep this will create more space between the shell and the instep. If this is not the case one runs the risk of hanging up the tuberosity of the 5th MT (the back end of the MT) on the shelf of the well the boot board sits it. This can lever the cubo-calcaneal joint and disrupt the stability of the mid tarsal joint causing the rear foot to pronate to compensate.

Unless the toes are large I usually have better luck shimming the forefoot. I also like to eliminate the toe spring as well as ensure that there is a consistent flat surface under the balls of the feet especially under the sesimed bones under the ball. Often you will find an elevation difference between the boot board and the shelf of the shell where the 2 meet. I am creating drawings of boot board shapes I will post this evening.

Lou said,
David:
Understand your explanation, however current teaching (at least race coaches) has athletes rotating the downhill foot about its long axis ( I will learn terminology you are using in this forum, perhaps we can just say supinating)and simultaneously abducting the downhill knee to begin the next turn. I think you have been talking about it here. If you block supination doesn't it affect this technique?

You say you prefer to shim the toes because of problems with the 5th met moving proximally which will cause pronation. I agree, but isn't it typically very difficult to add a toe shim without increasing toe spring?

Lou

David said,
Lou, it may be more accurate to state that the intent is to preserve a degree of tension in the arches of the feet and the lower limbs. It is possible to supinate a foot using inverters even with the foot loaded in a boot in this manner. But why would one want to? If coaches are telling skiers to do what you say they are then I believe they have no idea of how the human balance system works and that they should spend some serious time in medical libraries.

Yes you are right about shims affecting toe spring. That is why I would not go with more than 1-2 mm. Small amounts of toe spring are tolerable. But ideally I like to eliminate toe spring altogether. In order to make a boot skiable I used to end up rebuilding the entire thing if I was able to. This is why I no longer work on boots for anyone but myself, my wife and very close friends.

David said
Ric, once you get the aspects of your boot sorted out we have already discussed the next thing I do before I work with the instep fit is study the effect of buckle tension on the shape of the shell. On most 4 buckles boots I adjust the buckles as follows:

Toe Buckle #1 - keeps the snow out - 2nd bale catch with sufficient tension to compress the toe seal.

Instep Buckle #2 (a key closure) - loads the instep - 2nd or 3rd bale catch maximum depending on how much this distorts the interface of the shell lower with the cuff - I like to just tension the shell lower to the point where distortion at the interface starts but no more.

Lower Cuff Buckle #3 - loose but tight enough so it stays closed because it can load the throat of the boot and interfere with ankle dorsiflexion - my cuff has space with the shell in this area.

Upper Cuff Buckle #4 - snug but not tight because I need some low resistance movement for the ankle.

I play around with the micro adjustments to get the right load on the buckles. Then I almost never change the settings again. Once I have them set I work on bringing the tongue pad load up to the shell.

There is a widely held belief in the ski industry that the purpose of the ski boot is to clamp about the leg as tightly as possible in order to turn it into a big lever with which to "transfer energy to the ski" (Question: What does energy transfer have to with balance??). Foot function does not seem to matter. I see skiers whose boot fitter has added a thick pad to the shin part of the tongue and then installed shorter bales on the buckles so they can clamp their leg so tight the skier's nose almost starts to bleed.”

Should I go On? I've always hesited outing this info for various reasons, it has been really important to me, and it deserves to be shared.Especially in light of that other thread. Later, RicB.
post #2 of 25
Thread Starter 
david says:

Ric, Before I respond to your questions please give the following your careful consideration.

In a conducive environment the leg and foot are capable of producing instanteous explosive power for balance and propulsion. The issue is the control and direction of energy in the form of muscle/skeletal action not generic 'energy transfer'. By indiscriminantly enveloping and loading the foot and leg on their inner and outer aspects conventional ski boots 1) pollute sensory input essential to balance by adding foreign sources of input in planes other than the opposing vertical planes of balance and, 2) limit the action of joints essential to coordinated muscle activity. Wearing conventional ski boots is like trying to thread a needle blindfolded while wearing gloves with 2 inch thick padding.

In upright postures the most sophisticated source of sensory input for balance occurs in the nerves of the joints and pads of the feet. In the ski world the overwhelming majority of 'experts' believe that it is imminently logical to render the feet substantially non-functional with the structures of a ski boot. This is justified by the rationale that this is the only way to create an effective link with the ski.

Accepting that this thinking represents the best possible and perhaps the only solution effectively eliminates any opportunity for advancement. The fact that elite skiers who tested my invention consistently rated performance at 5/5 or 4/5 compared to their best ever highly modified conventional boots at 2/5 suggests the the majority in the ski industry are wrong.

In the current paradigm the tendency is to use the present technology as a gold standard to compare anything else to. In order to entertain the possibility of something superior you have to first recognise and then look beyond the limitations of the present standard you are saddled with.

RicB said: Sooo,,, I'm coming back to some things you have said in the past. Securing the foot over the instep is critical (I feel this for myself), systematic movement to load the trusses in the foot is critical to the process (I agree here too), ankle movement is needed to the extent that we want to allow dorsi/plantar flexion and pronation/suppination. Throw in suuport for the lower leg outside of the limited range of motion needed for dorsi/plantar flexion and we have something totaly different than my ski boot with custom hard cork footbeds and foamed in place race bladders.

Now we have Cam, the expert skier, skiing in boots two sizes too big, skiing with twice the control and comfort he's ever managed before. somewhere in that boot that was two sizes too big you had to be able to snug up over the instep, and snug up effectively around the leg shaft to handle all the perterbations of real world skiing.

first, I take it that length is not critical when the two above issues are addressed.

second, I would also assume that the hinge point on the cuff of this boot matched Cam's.

third, the forward lean angle matched what Cam needed with respect to the range of motion in his joints, ankle through hip, to achieve dynamic balance while skiing.

Enough for now. Again thanks for your time David. Later, Ric.



David says,Ric: Now we have Cam, the expert skier, skiing in boots two sizes too big, skiing with twice the control and comfort he's ever managed before. Somewhere in that boot that was two sizes too big you had to be able to snug up over the instep, and snug up effectively around the leg shaft to handle all the perturbations of real world skiing.

David: Yes you are right. Length is irrelevant once you are connected to the ski (length is an issue in walking in the boot) and the MACPOD boot used a very effective mechanism to contain the instep of the foot. The most common sensation reported by skiers who tested my boot was that it felt as if the base of the ski were attached directly to the sole of their foot with the inside edge of the outside ski running through the ball of the foot and even up and into the structure of the arch of the foot itself. The sensation of the ski base being attached to the sole of the foot was present even when the ski was not on the snow.

Once you have a rigid base you need some sort of mechanism that applies a force to the instep of the foot that is perpendicular to the transverse aspect of the boot base. The reason the force must be perpendicular to the transverse aspect of the base is that in adapting to the ground and establishing balance the foot rolls about its long axis after the outer aspect of the foot has made contact. This is the first component of balance.

Applying a force to the foot in this manner mimics the force that compresses and activates the arch when the weight of the body is positioned vertically over the foot so as to create an opposing vertical force with the ground.

The commonly held view is that a great deal of force must be applied to the foot to secure it against uplift in a ski boot. This is true in the current paradigm because the forces are not properly directed. In fact as you have confirmed conventional boots allow the foot to separate from the plane of the base. This is a big problem because it disturbs the function of the foot and with it balance. The trick to containing the foot is to prevent the instep counter from moving upward away from the base once it has loaded the instep of the foot. It takes very little force to load the foot. But the foot can apply huge force to the instep counter. So everything in the system must be very rigid and the instep counter must be fixed in position relative to the base. In addition, the instep counter must have the general shape of the instep of the foot as it relates to the apex of the lines (it does not have to be custom fit although this is beneficial). We used about a 3/8 in thick dense close cell foam between the rigid instep counter and the foot.

Ric: second, I would also assume that the hinge point on the cuff of this boot matched Cam's.
David: To a degree. It was not as critical as we first thought. But the boot cuff did actually hinge and not just bend like conventional boots. The cuff fit close to the leg (shin to calf) and it moved with the leg. It had about 5-7 degrees of zero resistance with increasing resistance at the end of foreward travel that was energy absorbing in nature (i.e. it did not spring back with significant force)

Ric: third, the forward lean angle matched what Cam needed with respect to the range of motion in his joints, ankle through hip, to achieve dynamic balance while skiing.
David: Definitely. The boot was set up so that the forward lead matched that of the skiers shin/ankle angle (there is little variation between skiers). the boot adjusted to the calf diameter at the rear and the the front of the cuff as in conventional boots which create forward lean angles that are tied to calf diameter.

There were a few very rewarding moments in the MACPOD ski boot project like first time Steve Podborski slipped out on to a technical slope in the Birdcage boot, made a few awkward turns and then flowed away effortlessly and gracefully exactly as I had predicted. It was also very rewarding to have skiers who I respect such as Cam Watson and Martin ski in the evolving prototypes.

Ric, you are right. The concept is very simple and elegant. But with few exceptions the industry fought me on every front. So the only option we have is to modify the existing format as best we can. I doubt that the performance of the MACPOD boot can be matched. But it is possible to greatly improve the existing technology. End of quote.


This is where I got to try out an instep pad for the first time. For those who contacted me for info, this is where it came from. I've installed them in the tounge in one boot and used them installed in my socks in two other. Everything David M and the others said about this approach to boot performance is true. I'm sure it probably doesn't equal the MacPod boot, as I never skied it I will never know. I do know that this insrtep pad hold down has infact given me a new freedom and comfort in my boots.

Installing them in the socks does work, and it does feel like the ski edge is connected right to the foot. I bought the foam David recomended, but I realized he does say that any good closed cell foam will work. I found that heat moldable closed cell foam, molded to my instep gives me all day comfort, keeps my foot down and loaded and doesn't break down.

For me, until some revolution in boot design comes along, I will never go back to a boot that I can't install these instep pads into. Right now I ski the atomic b-10. Some have said that most boots don't lend themselves to this method, it's been said about aomic boots also. But I've gotten it to work wihtout tearing into the liner wiht this boot. Especially because my foot profile fits the shape of the boot so well. My foot has room to move effectively along the lines that David recomended. Don't know if this would be true for everyones foot, and/or every boot. Anyway it is not hard, not exspensive. It takes mostly time and a little effort.

If you made it to the end here then you were at least somewhat interested., and you know where this whole instep pad came from. It works. Later, RicB.
post #3 of 25
sorry Ric... working on it... I'm just a but unwell atm,,, so cannot quite digest this,,,
also qords like "instep counter" I do not understand...
post #4 of 25
A very thought provoking post Ric.

Any chance of posting a pic of your 'in sock' instep pad to give me an idea of the size, shape & location etc.

Quote:
Originally Posted by RicB View Post
.....In the current paradigm the tendency is to use the present technology as a gold standard to compare anything else to. In order to entertain the possibility of something superior you have to first recognise and then look beyond the limitations of the present standard you are saddled with.....The concept is very simple and elegant. But with few exceptions the industry fought me on every front.....
I'm relatively new to skiing (2yrs = 11 weeks snow time) but was previously a high end competitor in another very technical sport & have always tried to 'look outside the box'. Boot fitting in the UK, with very few exceptions, is way behind the US with a custom footbed being about the best you can hope for. Adjusting forward lean, ramp angle & sole angles to integrate with the binding angles on the actual skis to assist correct balance & posture for the individual skier seemed blindingly obvious to me as my 'off the shelf' solution just would not let me adopt an effort free dynamically balanced stance.

I was lucky enough to have my boots properly dialled in by Bud Heishman at ESA 06 & then having my binding location checked by Steve Bagley on his Campbell Balancer. The improvment was immediately noticable.

Upon returning to the UK I've tried tried to find a retailer that can offer the same service & to tell as many skiers of the benefits. Your quote above is basically the kind of reaction I have received not only from the trade but also from skiers in general, none of which of course have actually tried any of these solutions themselves.

I'll need to re-read your post a few times to fully digest it but as I see it the concept is a new 'thinking outside of the box' idea to challenge conventional wisdom in that the instep pad can allow the boot (providing the other fitting criteria you've stated are correct) to give all the feel & control that's required but without the foot having the b'jesus squeezed out of it. That'd be nice.
post #5 of 25
Thread Starter 
Quote:
Originally Posted by disski View Post
sorry Ric... working on it... I'm just a but unwell atm,,, so cannot quite digest this,,,
also qrds like "instep counter" I do not understand...
Sorry to hear you are not feeling well Disski. It is a lot to digest. David called the instep clampdown device in his prototype an "instep counter". This would translate to my instep pad, though because mine is in a regular boot, some effectiveness is lost as I understand it. Oh,,,,to have skied the real thing. Later, RicB.
post #6 of 25
Thread Starter 
Quote:
Originally Posted by spyderjon View Post
A very thought provoking post Ric.

Any chance of posting a pic of your 'in sock' instep pad to give me an idea of the size, shape & location etc.



I'm relatively new to skiing (2yrs = 11 weeks snow time) but was previously a high end competitor in another very technical sport & have always tried to 'look outside the box'. Boot fitting in the UK, with very few exceptions, is way behind the US with a custom footbed being about the best you can hope for. Adjusting forward lean, ramp angle & sole angles to integrate with the binding angles on the actual skis to assist correct balance & posture for the individual skier seemed blindingly obvious to me as my 'off the shelf' solution just would not let me adopt an effort free dynamically balanced stance.

I was lucky enough to have my boots properly dialled in by Bud Heishman at ESA 06 & then having my binding location checked by Steve Bagley on his Campbell Balancer. The improvment was immediately noticable.

Upon returning to the UK I've tried tried to find a retailer that can offer the same service & to tell as many skiers of the benefits. Your quote above is basically the kind of reaction I have received not only from the trade but also from skiers in general, none of which of course have actually tried any of these solutions themselves.

I'll need to re-read your post a few times to fully digest it but as I see it the concept is a new 'thinking outside of the box' idea to challenge conventional wisdom in that the instep pad can allow the boot (providing the other fitting criteria you've stated are correct) to give all the feel & control that's required but without the foot having the b'jesus squeezed out of it. That'd be nice.
Well, I'm just the messenger spyderjon. The message is not mine, and believe me, there is much more info that I deleated, along with much more that I never copied in the first place. I just thought it was time to let this out a little. Especially in light of some of the PM's and email's I have been getting. People in the bootfitting industry or pro skiers who have dealings them seem are hesitant to open this up. they have much to lose. The communication to me however, has been that this man's research was correct and ahead of it's time, and resisted by the manufacturers.

I tried it to the best of my abilites, and am her to say it works, and if you read the posts, you will get an inkling of why. Me, I have nothing to gain or lose in this. But in light of the other "boot wizzardry" thread, I thought it was time the let it out. Pictures are a possibility. The foam I use is actully manufactured in the UK. Zote Foam. Later, RicB.
post #7 of 25
Quote:
Originally Posted by RicB View Post
Sorry to hear you are not feeling well Disski. It is a lot to digest. David called the instep clampdown device in his prototype an "instep counter". This would translate to my instep pad, though because mine is in a regular boot, some effectiveness is lost as I understand it. Oh,,,,to have skied the real thing. Later, RicB.
Oh I'll be fine... just a combo of a bit of jet lag and flaring up my chronic fatigue syndrome by doing way too much stuff while at home (and also jetlagged)...

the combo of 2 trips of 23 or so hours flying time and about 10 or so hours airport time... and 3 physio visits in a week and 1 property inspection and a few dinners to catch up with friends/family and 1 week skiing and 2 internal flights and 1 bus trip and 1 car trip and few more dinners and some time dealing with my friends recalictrant tennant... sort of took a bit of ooomph out of me... the basic body parts work fine but I am aching all over and my throat hurts and I have a heacdache and fever(like a low grade flu dose) added to that my brain just cannot function... I'm like a zombi.... just starting to improve today as my hands no longer scream when I try to type...

yes I would have loved to have tried the original...
Pity we cannot get him to make a few....
post #8 of 25
The technical information is fascinating and intuitively makes sense to have soemthing to hold down the instep. Perhaps it is in some other thead before my time, but for those of us who are more pragamtic and a little less intereted in the philosophy of the thing, the question may be, "how do i make/get an instep pad for myself to try it out?"
post #9 of 25
Quote:
Originally Posted by Mom View Post
The technical information is fascinating and intuitively makes sense to have soemthing to hold down the instep. Perhaps it is in some other thead before my time, but for those of us who are more pragamtic and a little less intereted in the philosophy of the thing, the question may be, "how do i make/get an instep pad for myself to try it out?"
Basically, you use closed-cell foam that you form over the top of your foot, starting at the back of your toes and going up your shins. I heated mine in the oven at a low temperature, put my foot up on a block, and formed the foam to my foot and lower leg. Unfortunately, the foam I used was too thick to actually work in my boots. I am going to try thinner foam next.
post #10 of 25
Thread Starter 
Quote:
Originally Posted by Mom View Post
The technical information is fascinating and intuitively makes sense to have soemthing to hold down the instep. Perhaps it is in some other thead before my time, but for those of us who are more pragamtic and a little less intereted in the philosophy of the thing, the question may be, "how do i make/get an instep pad for myself to try it out?"
It is a system, so reading the inital boot fitting guide should really guide you. That is why I started with the first post. Your forefoot needs some room to spread from loading. there should be more room on the lateral (outside) of the forefoot. If you have your foot cramed into a boot that requires you to unbuckle every run, it won't work. So I would suggest you go through the fitting routine outlined in the first post. The issue is the boot board ramp angle and possible footbed issues. Even at that it is really pretty easy process to just make one and try it, though the results will vary unless the full boot fitting process is followed.

I'll put together a step by step procedure, and those seriously interested can email me and I will send it out. Later, RicB.
post #11 of 25
Thread Starter 
Quote:
Originally Posted by ssh View Post
Basically, you use closed-cell foam that you form over the top of your foot, starting at the back of your toes and going up your shins. I heated mine in the oven at a low temperature, put my foot up on a block, and formed the foam to my foot and lower leg. Unfortunately, the foam I used was too thick to actually work in my boots. I am going to try thinner foam next.
Steve, you can grind it, or sculpt it with a razor knife, down to any thinckness, even after it has been formed. I take mine down to a fine edge at the perimeters, and I think the same can be done in the bulk of the area (field) too. I find that one of those snap off, cheap razor knives you get in the office supply stores work well, as you can extend them out 2 or more inches and sculpt the field very effectively. After I sculpt with the knife, I then sand with a block and sandpaper to smooth every thing out nicely. I wouldn't give up on this one yet. Later, RicB.
post #12 of 25
Thanks, guys. This makes a lot of sense.
post #13 of 25
Quote:
Originally Posted by RicB View Post
Steve, you can grind it, or sculpt it with a razor knife, down to any thinckness, even after it has been formed. I take mine down to a fine edge at the perimeters, and I think the same can be done in the bulk of the area (field) too. I find that one of those snap off, cheap razor knives you get in the office supply stores work well, as you can extend them out 2 or more inches and sculpt the field very effectively. After I sculpt with the knife, I then sand with a block and sandpaper to smooth every thing out nicely. I wouldn't give up on this one yet. Later, RicB.
Remember, RicB, you're far more effective at such things than I am.
post #14 of 25
Thread Starter 
Quote:
Originally Posted by ssh View Post
Remember, RicB, you're far more effective at such things than I am.
Well,,,if you are not going to use it why not give it a try anyway? Experiment and maybe expand on your abilities. You have nothing to lose now. later, RicB.
post #15 of 25
Funny, Dolomite built a five buckle boot that buckled down over the instep and kept the heel in the pocket, but discontinued the model when they joined with Tecnica. Hmm...I bought two pairs to hold me until the company brass comes to its senses.
post #16 of 25
Thread Starter 
Quote:
Originally Posted by nolo View Post
Funny, Dolomite built a five buckle boot that buckled down over the instep and kept the heel in the pocket, but discontinued the model when they joined with Tecnica. Hmm...I bought two pairs to hold me until the company brass comes to its senses.
Well as David points out, the problem with "buckling down" is that it also draws the boot in against the sides of the foot. A well fitted instep pad allows minimal buckle pressure so that the sides of the boots don't distort and pressure the sides of the feet, yet the foot is gently pressured down and lightly loaded and retained in place. Did you ever try out a pad in those dolomites Nolo? Later, Ricb.
post #17 of 25
Quote:
Originally Posted by RicB View Post
Well,,,if you are not going to use it why not give it a try anyway? Experiment and maybe expand on your abilities. You have nothing to lose now. later, RicB.
Completely true, but recall that I have the thinner foam that you sent me, so I'm going to try that, too.
post #18 of 25
Thread Starter 
Quote:
Originally Posted by ssh View Post
Completely true, but recall that I have the thinner foam that you sent me, so I'm going to try that, too.
Pink or grey steve? I would gladly send whatever you need to complete your trial. I recently bought a different scroll saw and I think I can slice the 1/2" in half without too much waste. Haven't tried yet, but I think in usable pad sizes I could do it. later, RicB.
post #19 of 25
RicB,

It has been a long time now but I spent many hours over the years with the inventor of the MacPod system you refer to and skied on a number of prototypes in the patent development days. The first prototype was a proof of concept birdcage model made of metal. It had a flat milled metal sole and was skied with no footbed. Kinda cold. A plastic bag covered the whole thing to keep snow off your socks. Despite poor fore-aft stops (on one version, none at all) the boot was very easy to balance in. It was a source of amazement to everyone but Dave how easy and natural it felt vis-a-vis balance. And also how easy it was to ski with bare foot on a flat surface. Sensory feedback was superior to any boot I have skied before or since. Prototype models all had three main features: instep hold down device that was controllable, a cushioning bumper on the inner aspect of the ankle to control pronation, and an upper that was hinged very low so that it moved with the leg. The concept provided progressive resistance with a sense of movement in the ankle, not pressure on the shin. The result delivered a skiing experience that is hard to describe because it was so unlike traditional ski boots that lean heavily on foot-gripping and pressure. All the prototypes that I skied in felt light, comfortable, very snow-sensitive and easy to balance in. Imagine a boot in which the forefoot area is so wide that nothing touches the sides of the foot. If you skied on a MacPod prototype you would find them easy and fun but not familiar.
It's worth noting that this concept came from years of experimentation with Steve Podborski's boots when he was winning world cup downhills. I saw those boots and was surprised to discover there was no liner or boot board inside. There was a fiberglass custom footbed bonded inside the boot, a rubber puck on the inside ankle and an instep counter attached to the tongue that was slipped in last. Otherwise he raced with sock feet inside an empty orange shell. He said it felt like his foot was in the bindings. He also said they were warmer than normal boots. The original idea was to market a kit to convert conventional boots by removing the liner and inserting the key elements but after a great deal of effort they eventually abandoned that idea because conventional overlap design poses so many obstacles that the results were not good enough. I have also tried for years to duplicate the prototype performance in conventional boots but without success. That's why they took the long and painful route to try develop their own boot design.
What appealed to me was that Dave's approach was innovative, not mired in unverified conventional dogma passed down from ski shop to ski shop, and was supported by scientific research, emperical data and very good field test results. For example there was considerable effort spent on calculating such things as optimum forward lean and ramp angle using biomechanics and such things as "sway." I think the patent is in the public domain and could be searched for detail although the patent is for a foot retention system that could be applied to ice skates or cycling shoes for example. It doesn't outline in detail how to build a ski boot.
In 30 years of skiing full time I rank my association with the MacPod effort as one of the epiphanies of my career. I hope in the decades since the story hasn't become more fantastic in the telling but I think I remember it correctly.
There is so much more to this story and I encouraged Dave to write a book about his 20 year stuggle against convention but he was too burned out to think about it then. Maybe I'll try again.
post #20 of 25
Quote:
Well as David points out, the problem with "buckling down" is that it also draws the boot in against the sides of the foot. A well fitted instep pad allows minimal buckle pressure so that the sides of the boots don't distort and pressure the sides of the feet, yet the foot is gently pressured down and lightly loaded and retained in place. Did you ever try out a pad in those dolomites Nolo? Later, Ricb.
I don't buckle it to the point it distorts the boot. I can't fit a sock in the boot, I doubt I can fit the foam in either. Besides, the boot seems to have the right design for me already and needs no modifications, other than a slight shave of the left boot sole to dial in the alignment.
post #21 of 25
Thread Starter 
Thanks for posting Martino. I was wondering if you were listening. What I know is that what David lead me through has turned my whole boot experience inot a brighter day. My tearing into the head boots was good, but sticking my foot into an Atomic bio-tech was really coming home for me. My foot had room where it needed it and there is room over the instep for a pad. Plenty of boot for me.

I wish he would write a book too. I hope he doesn't mind me sharing my own expereinces with his concept. I'm sure it is nowhere near the performance of the birdcage, but it is all I have at the moment. I'm even going to stiffen up the bootboard this fall to see if this makes a difference. It is already almost totaly flat with very low ramp angle. A new pad is in order too, as I have two years on my last one. Hopefully they haven't changed the boot for this year.

I had a bootfitter PM me saying the he thought David was correct and ahead of his time. Maybe his time is still to come, or at least maybe his ideas time is coming. Who knows? later, RicB.
post #22 of 25
zotefoams makes a 1/8 inch thick foam as well, although I'd think it too thin to be of any real use...
post #23 of 25
Thread Starter 
the directions are ready for those interested. PM or email me and I will send them to you. Later, RicB.
post #24 of 25

Ello all! Back in the trenches of wizardry I see!

I really think David's quote is remarkable >
In a conducive environment the leg and foot are capable of producing instanteous explosive power for balance and propulsion. The issue is the control and direction of energy in the form of muscle/skeletal action not generic 'energy transfer'. By indiscriminantly enveloping and loading the foot and leg on their inner and outer aspects conventional ski boots 1) pollute sensory input essential to balance by adding foreign sources of input in planes other than the opposing vertical planes of balance and, 2) limit the action of joints essential to coordinated muscle activity. Wearing conventional ski boots is like trying to thread a needle blindfolded while wearing gloves with 2 inch thick padding
I remember the old instep theory's (and new boot push) that sparked interest years ago. To me the concept was fun, but simply lacked understanding of foot dimensions to engineer a mechenism that allows the intertarsal joints to function in the pedestrian house of plastic known as a ski boot.
Tis great to see the wizardry team has continued to cast light on the quest for a divine solution of mating foot and ski! Was in the mountains last week! saw a dusting and tasted the chill in the air that makes you think powdah!

post #25 of 25
I jumped into this forum because I had 5 minutes to kill and it's been extremely interesting. I knew the ski boot was one of the most important parts of the skier/ski relationship, but to read up on the history of the skiboot as well as the science of it is amazing.

If someone was to write a book about skiing I reckon there'd be enough information in these forums alone to publish a series. There's a lot of knowledge and history being shared here and it's great to see it.
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