Ramp Angle

[Si]

Hi Harald,

I've got a new pair of AT/Powder skis this year that I've finally gotten a few consecutive powder days on. Even early on this season, without much soft snow, I felt that I was "back" on this setup (Atomic Snoop Daddys w/ Freeride Bindings). This was especially true in comparison to my other skis (Metron B5 w/ Neox).

I still have the footbeds you made for me and have canted my boot soles per your shop assessment (after a lot of on-hill experimentation that confirmed your recommendation). I also have worked hard to find the most effective forward lean and boot board ramp angle and have been pretty happy with my alignment in that respect.

Today I added about 3-4 mm of external lift under the boot heel and it definitely felt better. Any suggestions about how I might refine my approach and lock in on the proper amount of increased ramp angle? I certainly would prefer to have an on slope consultaton with you in regrads to this but that does not appear to be possible in the near future.

Thanks, Si

P.S. I'd be pleased to hear from any other alignment experts on this question.

[dewdman42]

I am anxious to hear what Harald has to say here also. I can say this much. All boot models have different ramp angles and so do different ski bindings. A few years back a lot of ski manufacturers were putting a lot of ramp angle into the binding plates. One pair of skis that I have from about 2003 have 10mm difference between toe and heel in the plate/binding setup. I am told that is a lot but I have always felt good on them.

I am told that current models of skis/bindings are reducing the amount of binding ramp back to 3-4mm. Seemingly they realized that it was a mistake to use so much ramp angle and now they are going the other way to flatter designs.

A local guy here talked me into adding lifters under the toes on those skis, and he added about 6-7mm of lift. That would supposedly get it to something like what a lot of current models are doing. I was so in the back seat all the time I couldn't stand it and pulled the plates back out.

Opinions seem to be all over the map about what the best ramp angle should be, which is a combination of your boot's zepa angle and the binding/ski setup. I'm not sure it should even be the same for all ski designs or all types of skiing either. But I will say, that a flatter ramp angle seemed to throw me in the back seat a lot. But maybe I just needed to get used to it also.

[BigE]

Quick question, no disrespect intended:

If you are being tossed in the back seat by too upright a ramp, does that mean that you can't flex the boot?

[Si]

The answer is yes I can get out of the back seat by pulling my feet under me and flexing the boots. The issue is trying to find a "neutral" that doesn't require more active effort to achieve fore-aft balance.

This is a good question, though, Big E. I would a gree that a skiers inability to flex the boots has quite a bit to do with finding themsleves blanced too far aft.

[stikki987]

Freerides are known for thier flat angle, it's very common to remove the toe shim and mount 1cm forward to compensate. This is a regular topic on the TGR board.

http://www.tetongravity.com/forums/showthread.php?t=55088
http://www.tetongravity.com/forums/showthread.php?t=62469
http://www.tetongravity.com/forums/showthread.php?t=63682

[h.harb]

Sorry SI for not answering sooner. This is the most complicated area in skiing and boot selection, as you know. I have to dig up some of my previous writing on this topic, as I know it is extensive and I don't want to leave anything out. We have had this discussion before.

We know that ramp angle on the inside of the boot does not yield the same results as ramp angle changes on the outside. We also know that lifting the front on the outside definitely puts you further back in stance and makes it harder to get forward. If someone is really over flexed and you have done everything correctly with the boot, such as spoiler changes and provided space behind the calf , you can next try lifting the toe on the outside. Not recommended however as this causes a dramatic affect. More later.

[BigE]

I've had good success with lifting the toes to get a skier into the FRONT seat! The issue was that the binding ramp was so huge and the knees were so far forwards that the knees were past the toes standing still. The hips were quite far back to compensate. They spent their skiing day consciously throwing their body forwards, and still not acheiving any tip pressure.

After the lift, the skier remarked it was so easy to balance it felt like cheating. They were well centered over their skis.

[dewdman42]

so if I hear what you're saying Harald, the boot ramp angle effects the angle flex. The binding ramp angle effects more the fore-aft location of the COM without effecting ankle flex so much. Yes?

[Si]

Thanks for the response Harald. As we have discussed before on a number of occasions, I recognize the complexity of ramp angle, zeppa angle, internal lifts, external lifts, and fore-aft balance. For those of you kind enough to respond let me give a little more detail. Standing with my leg in a neutral position (with the current external heel lift I've added) the front of my knee is about 1 inch forward of the front buckle forward edge. The total distance from the buckle edge to the end of the boot shell is about 2 inches. Thus, I expect that my knee is close to being over my big toe.

To just further support Harald's comment on the complexity I thought I'd relate some perceptions from yesterday and today (the last day for my current trip). With the added external heel lift on the Snoops my fore aft balance on my right turns has become better than for left turns (both are better than before). This is the reverse of what it was without the lifts - go figure. Perhaps it relates to the following: I have never been 100% satisfied with my alignment on my left. I believe, when I last adjusted the boot plate zeppa angle I think I increased the left. I will probably try to increase the right a little (it's a turn screw adjustment on my Dalbellos) to see if that makes any difference but it will have to wait for my next trip and next soft snow day when I take out the Snoops. I also wonder if thinking and tinkering with things this week will change how I feel about my fore-aft balance on my Metron B5's? Another thing to consider is that I had my left hip replaced about 11 months ago (right was replaced about 7 years ago) and it is continuing to get stronger and continually let me make better movements than previously. It's pretty strong, though, as I have been jumping off of 2-10 foot boulders all week. Yet another changing parameter.

[ramshackle]

Hey Si is there any chance your leg got longer as a result of the hip replacement surgery and now your stance is off from what it was before the surgery? Did you check your alignment after the surgery was healed and your leg strength got closer to pre-surgery?

[Si]

Hey Si is there any chance your leg got longer as a result of the hip replacement surgery and now your stance is off from what it was before the surgery? Did you check your alignment after the surgery was healed and your leg strength got closer to pre-surgery?

That's a very good question Ramshackle. It is something I've considered but I don't think it's too much of an issue in my case. The first reason is becaus ever since starting to ski this year, about 7 months after surgery, my alignment was improved and I was able to make a couple of adjustments to get it even closer to the right (which I'm very happy with). I had given up trying to further tune my alignment (not just fore-aft) on the left for the 2 years before surgery. This was because, the limited internal rotation and flexion were clearly affecting movements on that side. (I was skiing in a few PMTS camps with Harald when my first hip was deteriorating and Harald felt the same way). Immediately after surgery my left was "functionally" a bit longer. With time that functional difference has disappeared.

Secondly, the fore-aft issues I have asked about here appeared with one set of skis vs. another. Thus, I really don't think leg length discrepancy is an issue.

[BigE]

Thanks for the response Harald. As we have discussed before on a number of occasions, I recognize the complexity of ramp angle, zeppa angle, internal lifts, external lifts, and fore-aft balance. For those of you kind enough to respond let me give a little more detail. Standing with my leg in a neutral position (with the current external heel lift I've added) the front of my knee is about 1 inch forward of the front buckle forward edge. The total distance from the buckle edge to the end of the boot shell is about 2 inches. Thus, I expect that my knee is close to being over my big toe.

Are you looking for the center of knee mass to be over the big toe or the leading edge of the patella? Or are you looking for the center of knee mass to be over the arch of the foot?

Which one is "right"?

[Si]

Are you looking for the center of knee mass to be over the big toe or the leading edge of the patella? Or are you looking for the center of knee mass to be over the arch of the foot?

Which one is "right"?

For lateral alignment (which is not what I am discussing here) my understanding is to use the center of knee mass. For this fore/aft measurement of "neutral," static stance I was just using the front edge of the knee protruding the farthest forward.

I don't think that simple standards can be set as easily in fore/aft stance because of the number of degrees of freedom from flexion/extension of the ankles, knees, and hips, the interactions of forward lean and ramp angle, and the individuality of "natural" postures between individuals.

[BigE]

I don't think that simple standards can be set as easily in fore/aft stance because of the number of degrees of freedom from flexion/extension of the ankles, knees, and hips, the interactions of forward lean and ramp angle, and the individuality of "natural" postures between individuals.

I'll agree with you about "one size fits all" ramp angles, but not about location of CM. Ultimately, you've got to be able to get the hips over the feet. The limitations of degrees of freedom can make skiing dynamically more challenging, but I believe that there are some basic rules in stance alignment that must be followed.

[Si]

I'll agree with you about "one size fits all" ramp angles, but not about location of CM. Ultimately, you've got to be able to get the hips over the feet. The limitations of degrees of freedom can make skiing dynamically more challenging, but I believe that there are some basic rules in stance alignment that must be followed.

The difficulty I'm talking about is setting the correct lift under the binding after you have already set up or have been given the binding and boot settings. I don't think a static measurement doesn't work too well as with a given total ramp angle and forward lean a persons stance can still vary in a "neutral" cuff position. For example, one person may flex more at the knees and the waist (putting the butt back) than another - in response to the given parameters. (I actually did a study of 4 people showing that increased ramping in 2 of them moved the CM back and in 2 moved them forward in static off slope testing).

So my question remains, how do you quantitatively set up the final ramp angle without extensive testing on slope. In my case, I don't want to change my boot setup as my fore/aft balance feels great on one set of skis already. I'm looking to change the ramp angle on the other set to make them feel equal. BTW, just making the ski/binding ramp angle equivalent doesn't seem to do it because of differences in mounting and ski characteristics.

Do you have a suggestion for me? I could certainly use it as I want to add some heel lift to my Snoop Daddy/Freeride setup but can't figure out whether to live with the 3-4 mm I've been able to test with a lift between my boot and binding or do I go for more based on some other considerations?