Fore/aft boot

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Fore/aft boot

Postby h.harb » Tue Jan 11, 2011 2:58 pm

Just been PMing with Helluva skier. One statement I just sent to him should be shared.

The change of delta inside and outside on the sole of the boot; effects change of your hip position and its relationship to center. The softer forward flex of the boot, changes nothing about your fore/aft hip position. The front of boots are not there for you to flex, they are there for you to be supported.

One of the biggest misconceptions and myths, in ski shops, ski instruction and coaching, and in skiing is; getting a skier into a softer, or softening a boot, will move your hips forward. All it does is make you move further to get pressure to the front of the ski and flex plastic.

Of course this won't matter on early rise or reverse camber skis, because there is no front of the ski.
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Re: Fore/aft boot

Postby HighAngles » Tue Jan 11, 2011 3:05 pm

Thanks. I totally get that and it's been a real revelation this season skiing in my stiffest setup yet. It's about having a boot be responsive to your input and your body movements. As you said, a soft forward flexing boot does nothing but delay that input.

I always thought that to ski moguls well you should have a soft boot, but I've proven to myself this season that is simply not the case (as long as you're not playing "slam and pivot" in the bumps).

Anyhow, I'm still wrestling with the relationship between my boot ramp angle and the binding delta. I've reduced the forward lean on my boots as much as possible this season, but I believe I need some additional guidance on my fore/aft positioning. Obviously a day with the HH, Diana, or Chris needs to be in the works.
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Re: Fore/aft boot

Postby chris719 » Tue Jan 11, 2011 3:24 pm

Harald, thanks for sharing that, I had been told on one occasion that my weight was being kept back because my boots could be too stiff. Never made sense to me because I wasn't meeting any resistance, I was not making contact with the front of the boot at all.

As far as changes of delta inside the boot vs outside the boot, do you have any guidelines or thoughts on how their effects on fore/aft balance differ?

I understand this is a complex subject so there may not be a one-size-fits-all relationship.
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Re: Fore/aft boot

Postby HighAngles » Tue Jan 11, 2011 5:29 pm

I build my own custom bootboards so I've been able to play around with the boot ramp angle (inside delta). I've come to the conclusion that the boot ramp is inextricably linked to your boot fit. It changes the way your foot relates to the shell around it. So I ended up customizing my bootboards to have as little ramp as possible while still providing a good shell fit.

On the other hand, the binding delta (outside delta) seems to be the key (at least for me). Changes in this delta allow for modification of the fore/aft alignment without any effect on boot forward lean or boot fit. There's been so much talk in recent years of reducing binding delta as much as possible, but I don't think that goal can be viewed as an absolute without considering the entire system and how all the parts play into the fore/aft alignment. I have found for myself that I think I'm better off with more binding delta (5mm offset between heel and toe is where I'm at). I have messed around with shims that I can install between my heel piece and my plate. I just haven't had the opportunity to really scientifically evaluate these changes because I cannot quickly make them on the same pair of skis. I must switch between skis to quickly change binding delta, but then obviously a whole host of other variables are changing too.

Sounds like HH has a great "lab" setup with the ability to quickly make changes to the fore/aft alignment. Being able to get dialed in on this with HSS is definitely one of my goals.
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Re: Fore/aft boot

Postby Max_501 » Tue Jan 11, 2011 5:56 pm

Another thing to consider is that you cannot rely on 'feeling' for these fore/aft experiements. You need video to confirm that the changes are working.
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Re: Fore/aft boot

Postby HeluvaSkier » Tue Jan 11, 2011 10:23 pm

Max_501 wrote:Another thing to consider is that you cannot rely on 'feeling' for these fore/aft experiements. You need video to confirm that the changes are working.


That was actually what prompted the discussion between Harald and I. After viewing a few clips of some recent video, it raised some concerns about my boot set up. Based on "feel" the issues that are present would have never been detected unless I had a really good coach watching my skiing - but on video it is easy to see potential issues.
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Re: Fore/aft boot

Postby chris719 » Tue Jan 11, 2011 11:23 pm

Would it be correct to assume delta/ramp inside the boot is mainly to adjust the net forward lean (angle of tibia to foot) to a person's ankle range-of-motion, while delta outside the boot would then be adjusted to balance the person fore or aft?

Is there any case where it is preferable to "close" the ankle via toe lift inside the boot when you can lift the toe outside and not alter ankle range-of-motion?
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Re: Fore/aft boot

Postby chris719 » Thu Jan 13, 2011 10:50 pm

Quick question for those who have experience tinkering with their fore/aft setup... does anyone have any exercises or tips that are good indicators if you are on the right track with adjustments?

For example, what to look or feel for when you adjust things like binding delta.
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Re: Fore/aft boot

Postby h.harb » Thu Jan 13, 2011 11:18 pm

You sense the tip of the outside ski pulling through the arc right to the end. Or the alternative, you sense you are waterskiing on a very slow tow boat and the only thing you can see is the water between your ski tips.
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Re: Fore/aft boot

Postby HighAngles » Fri Jan 14, 2011 4:08 am

HH points out the feel of correct fore/aft alignment. I would say that when correctly aligned both the tip and the tail of the ski is equally available to you. If your alignment is too far forward you'll be dealing with either tails that wash out easily or you'll be doing a lot of backseat driving. If you're too far back it will be harder to get sufficient pressure on the tips and get them to engage.

As Max_501 mentioned, I agree that you really need to get some video (or have someone knowledgeable ski with you) to assess this alignment. You can't trust your own biofeedback until you can reinforce what you're doing in your skiing with what the video shows or what the alignment specialist tells you.
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Re: Fore/aft boot

Postby Matt » Fri Jan 14, 2011 6:13 am

You can compensate for these angle issues by moving hip fore or aft, and that will tire different muscle groups, and IMO that is the tell-tale of bad alignement. An external observer can easily see it by watching hip placement.

I think it is also interesting how some of these parameters affect the lateral balance. If the soleus is not close to isometric state the lateral balance will be affected. I'm no expert in biomechanics but it is quite interesting to experiment with the cuff and ramp angle to try this out.

You are lucky in the US regarding these things. There seems to be a lot of focus on alignment and a lot of good fitters. In Sweden the general public is pretty unaware that there even is such a thing. If you do know about it, it's quite a challenge to find a good fitter. Among young racers I see a lot of alignment issues. Many of them haven't even aligned the canting.
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Re: Fore/aft boot

Postby h.harb » Fri Jan 14, 2011 9:39 am

Your own feedback, self evaluation, about where you stand and how you ski is worthless. It stays that way until you reach the black level and even then, you probably have to use video to find the details. I use video to work on my skiing as often as possible.
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Re: Fore/aft boot

Postby Erik » Fri Jan 14, 2011 1:35 pm

My recent experience on this subject...

During the Super Blue Camp, Chris and Diana were both giving me feedback that I was in the back seat - a lot.

Practice makes Permanent. Perfect Practice makes Perfect. I started out for a year before I found PMTS in Dalbello Krypton boots, and the first two years in PMTS in those boots. Even though I was trying to practice PMTS movements, the ramp angle on those boots was ingraining the habit of being in the back seat. Switched to Head Raptor 125 beginning of last season, but being in the back seat is still the position I revert to when I'm not really focusing.

External feedback is really necessary for fore/aft position. For me, proprioception of fore/aft, while moving on skis, is really hard. Diana would tell me that my static position was fine, but after every run she would tell me that I was in neutral at best (even though I thought I was as forward as I could get). At one point, she had me get in the proper position statically, then she physically got down and rotated my skis as if I was on a turntable to point me down the gentle slope, then sent me off. She told everyone in my group to watch. At the end of the traverse, I looked back and got the thumbs down. I was told that I moved back into the back seat within a ski length or two once I started moving, and I never felt it!

I had my upper buckles and power strap set at what I thought was a reasonably neutral upper tightness. Trying for proper fore/aft, I could flex the boots forward, but I felt like my leg movements were very "locked out" in that position. I know that what it felt like is that only the upper part of the shin was in real solid contact/support with the tongue of the boot. Eventually, after further consultation with Diana, I tried substantially tightening the upper buckles and booster strap. What I then felt was a much better contact in the front of the boot. Diana then tried the drill of getting me moved into proper static position again at the upper pitch of Sundance, then shoved me off. This time, I could start to feel myself going to the back seat very shortly after I started moving. Reacting to that by pulling the feet back, I suddenly found that my pullback movement was more effective, and I wanted to be forward. Suddenly, I felt in much more control of my skis. I did what felt like my best skiing of the week. Looking back up at my cheering group at the top of the pitch confirmed that I had achieved the proper results.

That didn't magically solve everything for me. In the short amount of skiing left on Friday morning, I had some mixed results; still getting back somewhat, but in general more fore than aft. After I snugged up the upper part of the boots, I found that I could lift the tails in static position without the big strain that it previously was to try to get them off the snow...I may try to see if that works as one test of my boot adjustment, and supplement to confirm that I can do some tail flappers in motion.

I am off to ski again this weekend to see if I can continue on the right trend to fix my fore/aft. However, an important part of that skiing will be to get my ski partners to observe me and give feedback on the fore/aft position.
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Re: Fore/aft boot

Postby h.harb » Fri Jan 14, 2011 1:55 pm

Thanks Erik, these posts about what you discover at camps or in lessons are highly informative and valuable. Not too many though, we want skiers to come to camp, not to just read the forum to improve. We know PMTS works by reading and applying, unfortunately. Just kidding of course.
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Re: Fore/aft boot

Postby WNYSkier » Fri Jan 14, 2011 9:00 pm

OK, I'll bite.....So why do manufacturers make different flex index boots?
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