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Maybe you need two of those plates, one mounted backwards.
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Binding ramp angle differences
- Thread starter jonc
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Don't know about Fischer's offering, but that's exactly what Atomic's Ramp Tech does. It appears to be simply a ramp under the heel piece that is higher towards the rear. Thus, as the ski flexes, which forces the heel piece backwards, the height of the heel piece is raised. It thus imparts an added delta that's in proportion to how deeply the ski is flexed. In accomplished skiers the maximum flex, and thus maximum delta, should be at/near the apex of the turn.
Personally, I think this is a terrible idea. It pushes you into a higher ramp angle in the belly of the turn, which would certainly screw with my balance. I would be very surprised if any of their sponsored alpine racers use it, for that reason.
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Your point about not always being able to rely on your feelings is a good one (though my suspicion is that fore-aft is one adjustment where feelings, and what's objectively superior, align). Ideally you'd send video of yourself with different deltas to a coach whose eye you trust, and combine this with timed runs (just as you did in verifying your improved performance on the larger radius GS skis). Of course, your current fore-aft may be fine.
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It's been my experience that fore-aft is trickier to adjust than lateral canting—a good aligner can usually get your lateral canting pretty close in the shop, but dialing in fore-aft often requires on-snow testing. Perhaps what you mention is part of the reason for this. Though I'd say the main reason fore-aft is tricky to get right is that it combines three different things -- delta, zeppa (bootboard angle), and forward lean (and that's just the skier's inherent fore-aft; there's also the fore-aft position of the skier on the ski).
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Ever wondered how much so-called "boot stiffening of the center portion of the ski" as felt by the skier was actually dynamic delta changes? Me too.
I spent a lot of time researching delta. I found a very knowledgeable expert at Pierce Skate and Ski. Bart has done studies on ramp angle for several years. This year I bought a couple of new head cheater skis that I demoed last winter which were at 4 delta and my new Head Pro 16 bindings are at 7 delta. After talking with Bart I went with +3 on both Heads and on my new FIS slalom. I have extra shims and all of this is just a good guess until I ski them. I guess time will tell. I know I can tell a .5 degree cant difference on my boots. Dont know if I can tell the difference in Delta.
I guess we can get as scientific as we want or we can go simply by feel and experimentation. I prefer to go by feel and of the thought that if some feels good go farther until it doesn't feel good. Then work back and forth until nirvana is found. When focused on the sagittal plane there are a few things I have discovered and use for my reference as to how close I am to ideal.
1) one legged skiing ability
This may sound simple but in order to balance effectively on the little toe edge the lower leg angle needs to be correct. If the lower leg angle is too steep, balance on the little toe edge is very challenged as the hip is forced to move aft of the feet in an attempt to remain in balance and the ability to guide the ski effectively is severely compromised. When the lower leg angle is correct, the skier can remain in a relatively taller stance and move the hip ahead of the BoS using the stiffness of the boot cuff to modulate pressure to the forebody of the ski and the little toe edge. If the lower leg angle is too upright the skier must compensate for losing the leverage advantage over the boot cuff by breaking excessively at the waist just to balance.
2) series of short swing turn balance
While linking a series of short swing turns down the fall line, the skier should feel they are able to remain in stable fore/aft balance without osscilating back and forth searching for the sweet spot.
3) body position (ie: parallel lower legs with spine)
When viewing the skier from the side observing the sagittal plane while linking turns, the skier's lower leg angle should pretty much parallel the skier's spine angle and flexion extension movements should articulate primarily from the knee and hip joints maintaining the parallel relationship of the lower legs and spine throughout. In general, if the lower leg angle is too steep the spine will be too vertical and if the lower leg angle is too vertical the spine angle will be too steep.
4) ability to effectively transfer impulse to the forebody of ski before the fall line. ie: turn entry during platform establishment.
When optimum lower leg angle is achieved the skier should feel a solid contact between the shin and the boot tongue at the very top of the turns, facilitating the ability to pressure the forebody of the ski effectively. This "primed" position gives the skier the most options at initiation as they will have the ability to crush the front of the boot and pressure the ski shovel or modulate any degree of rotary impulse to the ski, or tip the ski aggressively on edge. Basically it gives the skier the most options to effect all the skiing skills.
1) one legged skiing ability
This may sound simple but in order to balance effectively on the little toe edge the lower leg angle needs to be correct. If the lower leg angle is too steep, balance on the little toe edge is very challenged as the hip is forced to move aft of the feet in an attempt to remain in balance and the ability to guide the ski effectively is severely compromised. When the lower leg angle is correct, the skier can remain in a relatively taller stance and move the hip ahead of the BoS using the stiffness of the boot cuff to modulate pressure to the forebody of the ski and the little toe edge. If the lower leg angle is too upright the skier must compensate for losing the leverage advantage over the boot cuff by breaking excessively at the waist just to balance.
2) series of short swing turn balance
While linking a series of short swing turns down the fall line, the skier should feel they are able to remain in stable fore/aft balance without osscilating back and forth searching for the sweet spot.
3) body position (ie: parallel lower legs with spine)
When viewing the skier from the side observing the sagittal plane while linking turns, the skier's lower leg angle should pretty much parallel the skier's spine angle and flexion extension movements should articulate primarily from the knee and hip joints maintaining the parallel relationship of the lower legs and spine throughout. In general, if the lower leg angle is too steep the spine will be too vertical and if the lower leg angle is too vertical the spine angle will be too steep.
4) ability to effectively transfer impulse to the forebody of ski before the fall line. ie: turn entry during platform establishment.
When optimum lower leg angle is achieved the skier should feel a solid contact between the shin and the boot tongue at the very top of the turns, facilitating the ability to pressure the forebody of the ski effectively. This "primed" position gives the skier the most options at initiation as they will have the ability to crush the front of the boot and pressure the ski shovel or modulate any degree of rotary impulse to the ski, or tip the ski aggressively on edge. Basically it gives the skier the most options to effect all the skiing skills.
Lots of debate. All I know is that delta matters to me, and it is even more important as I have a short boot sole length.
That being said, I'm in the market for bindings. I want flat. Does anyone know what frame bindings (dukes, barons, tours, adrenalines, etc.) are flat?
Mike
That being said, I'm in the market for bindings. I want flat. Does anyone know what frame bindings (dukes, barons, tours, adrenalines, etc.) are flat?
Mike
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I think the Dukes are the closest, I have a shim under my heels to get them closer.
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You mean shim under your toes, right? [If you're trying to get them closer to flat.]
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No, under the heels, they are toe high, but not as much as most AT bindings are.
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According to Tyrolia's 16-17 datasheet, the AAADRENALINS (did they use that name so they'd show up first on an alphabetical list?) have adjustable deltas. The AAADRENALIN 13's is 4.0 – 10.5 mm (both short and long versions), and the AAADRENALIN 16's is 3.0 – 9.5 mm (both short and long versions). Perhaps someone else can supply data for the Markers.
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I wonder how/why Tyrolia is variable (other than shimming).
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Interesting! I don't know anything about AT bindings; why would they typically have negative deltas?
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Hinging the toe takes up some space.
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Again, don't know anything about AT bindings, but that table is for differences in pin heights, which are going to be different from deltas (differences in sole heights) unless the vertical distance from the toe pin to the sole is the same as the vertical distance from the heel pin to the sole. Based on the pics, though, it looks like the latter is much greater than the former. But assuming those distances are industry standards, you could convert the pin height differences to deltas. I.e, if:
distance from heel pin to sole = x
distance from toe pin to sole = y
Then delta = heel sole ht. - toe sole ht. = (heel pin ht. - x) - (toe pin ht. - y) = heel pin ht. - toe pin ht. + (y - x)
So all you need to know is (y - x) to convert the table you linked to deltas.
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I think that it is unless you love skiing in the backseat!
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OK, but why wouldn't they put some material under the heel to compensate, to make the deltas more conventional (i.e., non-negative)? In alpine boots, most skiers would struggle with a negative delta. So is there something about AT boots that makes negative deltas suitable?
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@Mike King is asking about frame bindings, the Wild Snow table is for tech bindings.
