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Technical goldmine

post #1 of 13
Thread Starter 
I've been looking into the services provided by Lou Rosenfeld. His organization provides technical services. These are the kind of services provided to Worldcup level skiers.

see: http://www.lous.ca/

While roaming his website, I came across this; http://www.lous.ca/techarticles.htm

The contents include;

Is the Campbell Balancer an Effective Tool for Deter-mining Ski Binding Position
The purpose of this research was to determine skier preference for one of two binding locations (bal-anced position or manufacturer stipulated position) and to determine inter and intratester repeatability of the balancing tool.

Research & Race Boots: The Perfect Fit
(Ski Racing September 13, 2005 - Buyer's Guide Issue)

As consumers, racers and coaches, we've come to believe that the dogma of skiing is based on science. My experience in science and bootfitting has shown me otherwise. Where has our knowledge of alignment, balance and binding position come from? Has that knowledge been suported by real research? If not, what should you be doing to make your skiing faster, easier and more balanced?

For Easy Skiing and Balance, Modify Your Equipment to Work for You!
Don't modify your technique to suit your equipment. Production methods, industry standard boot position marks and our own anatomical differences have ramifications which are seldom considered.

Ramp Angle
Probably, some ramp angle forces us to assume a slightly bent knee, ready athletic position. The tensed muscles necessary to maintain this position are more quickly able to respond to changes in balance and terrain. So, while ramp angle may not be the only tool needed to solve a skiers balance problem. Changing it may be part of the solution.

Footbeds, What Should We Expect?
A good pair of orthotics may make you more comfortable, and if properly made may not interfere with foot function. Improperly made (too much arch support or rigid arch support for example) may actually hinder skiing.

How Tight is Too Tight?
Biglines.com Column 4 (2003-2004 Season)

Shouldn't boots be as tight and close to the foot as possible to transfer our energy to the ski? Maybe! I imagine it would therefore follow that the best and most functional race boot would actually have no liner and the plastic shell would have been directly molded to the foot and leg, absolutely locking them together. Painful! No doubt. But what a racing machine! Maybe.

"Footbeds, Necessity or Nicety?"
In addition to thinking orthotics reduce pronation it is also believed orthotics reposition the foot to a more powerful and stable neutral position. Finally, since foot motion and tibia rotation are coupled at the ankle (if you move one the other must move), anything that acts to resist pronation also resists leg rotation necessary to edge skis and resists the subtle foot motion so necessary for easy and effective balance.

Binding Position Article
(Ski Canada)

I believe, am convinced, have tested and conducted research to determine that the position of the boot on the ski is critical for balance, and often is not close to the optimal position for individual skiers. To ski consistently at your best, easily and safely you must be mounted in the appropriate spot for you on the ski.

What Role Does Equipment Play in Skiing?
(Alberta Alpine Super G Magazine)

Skis are for transportation, boots transfer our movements to the skis, and bindings are simply to keep us safe. The function of boots should be to aid our skiing by permitting us to assume a natural and comfortably strong position and balanced posture.

The Effect of Ski Binding Position on Performance and Comfort in Skiing
by Benno Nigg, Hermann Schwameder, Darren Stefanyshyn and Vinzenz von Tscharner;
Human Performance Laboratory, University of Calgary and Institute for Sport Science, University of Salzberg

Turning in alpine skiing depends, among other factors, on the forces applied from the skier to the skis. Theses forces depend on the skier, and the ski and the position of the binding on the skis. Based on this knowledge skiers train to improve technique and muscle forces applied ot the ski during skiing.

The Effect of Binding Position on Kinetic Variables in Alpine Skiing
by Benno Nigg, Hermann Schwameder, Darren Stefanyshyn and Vinzenz von Tscharner;
Human Performance Laboratory, University of Calgary and Institute for Sport Science, University of Salzberg
Turning in Alpine skiing is a highly dynamic locomotion primarily determined by the skills and the equipment of the skier as well as by the snow and slope conditions. The turning characteristics of the skis are affected by the material properties, the ski geometry, the stiffness of the binding riser system and by the position of the binding on the skis.

I think I'll be busy for a while...


post #2 of 13
Wow, technical goldmine is a gross understatement. These articles address just about every topic being posted in these forums.
post #3 of 13
Lou is brilliant, experienced, and of the highest caliber. Everyone should read these articles! Thanks for pointing them out; I didn't realize that he had posted all of them!
post #4 of 13
Thanks for the compliments, but please my first Master's supervisor would not agree with the brilliant part guaranteed. And everyone should know that there are others on this site with equal if not superior backgrounds that may just not put pen to paper. Bud among them.

For people that are interested in the papers on my site I hope you enjoy them and am certainly interested in feedback. However for shops this is a busy time of year so please don't be offended if I don't immediately reply. We had intended to keep the site more regularly updated with scientific papers but just haven't been able to keep up.

Hopefully now that we have a new webmaster that will be possible. There is much good stuff out there.

post #5 of 13
Lou's being modest.

So Lou, have you come up with a reliable way to measure ramp angle of boots that don't have it built in to the boot board? I know that after my first mods on the head boots that David lead me through, I can feel it immediately when I try on a boot with too much ramp. Forward lean also. Once I experienced a balanced upright stance there was no going back. At least for me.

I look forward to more from you and your web site. Keep up the good work and thanks for sharing your hard earned knowledge.
post #6 of 13
Thanks to barrettscv for posting the links. Thanks to Lou for writing and posting the articles for general consumption. Very nice work!
post #7 of 13
Originally Posted by nolo View Post
Thanks to barrettscv for posting the links. Thanks to Lou for writing and posting the articles for general consumption. Very nice work!
post #8 of 13
don't understand your question. Measure ramp angle of boots that don't have it built into the boot board? What are you asking? Do I have a way of measuring ramp angle or is there a way to determine correct ramp angle?
post #9 of 13
Originally Posted by race510 View Post
don't understand your question. Measure ramp angle of boots that don't have it built into the boot board? What are you asking? Do I have a way of measuring ramp angle or is there a way to determine correct ramp angle?
Some have the ramp built in to the surface that the boot board sits on, while with others you can take the boot board out and use a simple protractor to measure the angle. I was wondering if you have devised a way to measure those boots that have it built in to the bottom of the boot.

My new atomics are like this. The boot board is just a flat sheet. So to measure exactly would require some type of adjustable angle finder that could be slipped in to the boot. Was wondering how you measured this angle or do you simply rely on testing with the boot on?

Because I did originally modify a boot board (DavidM's process) that I could measure out of the boot and ski it for a year, I have a good feel for the right angle for myself, but I would like to get more specific.
post #10 of 13
Now I got it. Yes Atomics are just flat plastic and ramp is actually built into shell. I admit to not being partial to this design as it limits options for fixing a problem ramp.

That aside I will also mention that your assumption (also mine until just two years ago) that removing the zeppa and measuring the angle of it outside the shell will not result in accurate results. Turns out several manufacturers do build slight ramp into shell by making boot sole thicker in the heel area than in the toe area. so although most ramp is in the zeppa there is still a degree or so in the shell. Only dependable way is to measure zeppa angle in the boot. I do it with a very simple tool I had made.

If I could figure out how to attach pictures to this reply I would send one. Please help. Otherwise imagine a flat bar (1"X1/2"X 10") with feet approximately 12" attached at right angles to the bar and parallel with each other. So that when the feet are set on a flat surface the bar is parallel the surface but elevated by 12". The flat bar is slotted at one end so a foot can slide in order to fit into different size boots.

I use a tool to hold the boot open at the two forefoot buckle and position the bar so one foot is against the zeppa in the heel area and the other is against the zeppa in the toe area. The upper flat bar is now parallel the zeppa.

I mount a digital level on the bar which gives me an instant readout. Also use the same tool to measure binding ramp.

Is this clear?

Regarding testing with the boot on the answer is yes and no. I am not comfortable with a scientific method to determine correct angle, although from a thread elsewhere with Bud, Shh and I think you maybe there is some progress about to be made.

I rely on experience and observation of the skier stance in the store to determine correct angle but I always like to know the actual starting point. so I use the tool to measure boots and bindings.


post #11 of 13
Well the new Atomic boots do fit me well, and the B/M series are pretty flat in the Zeppa (I guess) angle. I was told these two boots in the atomic line are the flattest in the industry by another well recognized boot fitter/pedorthist. I know when I try on atomic boots every fall I try the race tech CS (totally different kind of boot board too) and find the angle in those to be way too steep, I feel it right away. I like the idea of your device. Much easier to get just a post into the boot than an entire measuring device. Might have to make one of those up from some scrap maple. For me the forward lean on the atomics is easier to modify than the heads I first did. I'm about to start on my new M110 this week.

Being an atomic adviser I have to wear atomic boots, but so far this has not been a hardship, quite the contrary, it has been a pleasant surprise, with much less modifications needed in a shorter boot (the last really fits my foot) which gave me more usable performance. I still swear by the instep pads though, but I now put them in my socks as Martin Olsen suggested. Thanks Lou.
post #12 of 13
Thread Starter 

Adding picks is possible, follow this advice: http://forums.epicski.com/showthread...picture+thread

post #13 of 13
I'll try to get this post picture thing sorted thanks to Michael's post. I have little patience when fighting computers however.

Agree with you in part about Atomic boots. haven't been in love with liner and other quality issues since the beginning but they are making strides. I agree they are flatter than most and with flat binding it seems they have some understanding. My problem with this type design is that if necessary to change, then it is difficult to impossible inside the boot.

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