Ramp Delta Angle Question

[Pinelander]

I will be getting my new boards - Kore 93's, and bindings - Knee bindings, setup. I normally have my skis balanced to get me in a more forward position. Consequently my toes get raised. I know that the ramp delta angle is dependent on several things, length of the boot sole being one. Prior to setting up the bindings (Knee's) what would be the best setup for me to order for the Ramp Delta...6mm, 4.5mm, 3mm, or 1.5mm? Bearing in mind that the setup will be balanced to keep me more centered (forward) Thanks!

 

[Chris Geib]

Assuming you will be using the same boots...

Measure the delta on one of your existing skis that works for you and replicate that!
On the old measure from the ski base to the contact points on the bindings.
Then on the new setup be sure to take into consideration any delta created by variations of ski itself and (combined with) that of the binding.

Delta or Delta Angle is related to the bindings & ski - under the boot.
Positive=Heel higher than toe
Negative=Toe higher than heel
Ramp is the angle of the boot board or zeppa inside your boot.

 

[otto]

I would mount the bindings in the stock position, using the manufacturers recommendation for placement on the ski. Then proceed to the mountain and ski. If everything feels good continue skiing on the set-up as it is.

 

[MRT]

Knee binding makes a lifter kit (4.5mm thick with the longer screws) that is shaped correctly to fit under the toe piece to affect delta---your dealer should be able to get them---the lifter doesn't eliminate all of the delta as there is a a 7mm diferential so you end up with 2.5mm.

Delta shouldn't exist---as you may know it came about when the manufacturers added brakes to the heel pieces.

Mike

PS: Playing with "Delta" is an effort to overcome an inappropriate "centered up position" caused by the combination of your calf circumference and your boots forward lean---so you could solve the problem a different way---by changing the boots forward lean, to position your torso correctly just ahead of the boot sole center, determined by your calf circumference. Bigger calf=less forward lean----skinny calf= more forward lean.

Ultimately you have to get the Tibia angle to the right position in order to have the stack of bones above oriented correctly---Tibia angle is affected by the boots forward lean and the size of you calf at the top of the liner.

Fore/aft balance can also be effected by the boot board angle and delta angle---tilting the boot (gas pedaling it) has a limited effect and teeters the boot, changing the effective forward lean of the tibia and moving load to the rear of the foot, it does work, but is limited.

 

[JDV]

Knee binding makes a lifter kit (4.5mm thick with the longer screws) that is shaped correctly to fit under the toe piece to affect delta---your dealer should be able to get them---the lifter doesn't eliminate all of the delta as there is a a 7mm diferential so you end up with 2.5mm.

Delta shouldn't exist---as you may know it came about when the manufacturers added brakes to the heel pieces.

Mike

PS: Playing with "Delta" is an effort to overcome an inappropriate "centered up position" caused by the combination of your calf circumference and your boots forward lean---so you could solve the problem a different way---by changing the boots forward lean, to position your torso correctly just ahead of the boot sole center, determined by your calf circumference. Bigger calf=less forward lean----skinny calf= more forward lean.

Ultimately you have to get the Tibia angle to the right position in order to have the stack of bones above oriented correctly---Tibia angle is affected by the boots forward lean and the size of you calf at the top of the liner.

Fore/aft balance can also be effected by the boot board angle and delta angle---tilting the boot (gas pedaling it) has a limited effect and teeters the boot, changing the effective forward lean of the tibia and moving load to the rear of the foot, it does work, but is limited.

Mike - I have been struggling to find the best boot fit for the last few years. I haven't found anyone in my home area that understands anatomy and the biomechanics of skiing well enough to help me. Everything you said above FINALLY makes so much sense to me!!

I am a short girl - 5'2 with VERY large calves. This causes my dorsiflexion to be maxed out when standing in my boots done up. It has majorly impacted my skiing and I can't get past a certain point in my development because of this aggressive forward lean caused by my anatomy.

In the past, I have used a heel lift - but I don't find that it works well enough (plus it's like skiing while wearing high heels which actually causes my calves to get bigger!) and I can't get a boot upright enough to actually solve this issue!

Is there any info that you could pass on that would help me?

I was looking at Ficher vacuum boots as these might be able to mould the upper cuff to accommodate? BTW any women's boots with a tulip shape don't properly fit my feet (the lasts are WAY too big) and they are way too soft. I am currently skiing in a lange race boot 120flex.

 

[Philpug]

@JDV I imagine you thighs were also burning after a day of skiing too. A Lange 120 SC (Short cuff)? A good option of a boot since it is oen of the more upright boots on the market. Do you have the heel lift in these? A heel lift should open your ankle, not close it, it increases your range. The heel lift should also give a bit more room around your calf since it is rasing it out of the boot some. Do you have the spoiler removed? Has anyone flaired or cut down the cuff? While removing the spoiler and flairing the cuff that will help preventing your calf from pushing your leg forward too. Also, what binding are you in, does that have a high delta? Assuming at 5'2" you are in a fairly short boot this will be even more pronounced. As Mike says a gas pedal or a lift under the toe piece might help too.

 

[RuleMiHa]

Mike - I have been struggling to find the best boot fit for the last few years. I haven't found anyone in my home area that understands anatomy and the biomechanics of skiing well enough to help me. Everything you said above FINALLY makes so much sense to me!!

I am a short girl - 5'2 with VERY large calves. This causes my dorsiflexion to be maxed out when standing in my boots done up. It has majorly impacted my skiing and I can't get past a certain point in my development because of this aggressive forward lean caused by my anatomy.

In the past, I have used a heel lift - but I don't find that it works well enough (plus it's like skiing while wearing high heels which actually causes my calves to get bigger!) and I can't get a boot upright enough to actually solve this issue!

Is there any info that you could pass on that would help me?

I was looking at Ficher vacuum boots as these might be able to mould the upper cuff to accommodate? BTW any women's boots with a tulip shape don't properly fit my feet (the lasts are WAY too big) and they are way too soft. I am currently skiing in a lange race boot 120flex.

Where are you?

Even though a heel lift would lift your calves out of the boot which would decrease the dorsiflexion problem, wouldn't it still tip you forward so you would be trading one problem for another and getting the same result?

What about an aftermarket liner where the cuff is heat moldable? I have the opposite problem (I need more forward lean), and when I molded my Intuitions (convection oven) for the third time the volume of the cuff decreased so dramatically I actually had to build it back up with a spoiler. I've also heard of other ways to decrease the volume in the intuition cuff (peeling and cutting out extra).

I also had a problem where a too long boot (it was an LV, so appropriate width) with a high volume liner around the ankle (so that it was buckled to only the first or second latch) caused my lower leg to have a more upright angle in comparison to a low volume liner buckled down tightly in the same boot. It seems as though when the ankle latch was tightened down with a low volume liner it pulled my ankle into the boot heel pocket so my leg was forced to mimic the geometry of the boot, but when a high volume liner was used my foot slid down relative to the heel pocket which forced a more upright lower leg.

I've also had my ankle padded in the past (I have narrow ankles and normal/large calves so it's historically been a problem) and when they pad behind the malleoli it pushes my leg forward and upright and when it's padded in front it pushes it back with more forward lean.

Most of these things were a nightmare for me, and they are not considered good bootfitting practices (and would decrease control because of increase in distance between foot and boot), but if you are miserable, maybe it's worth playing around with $5 bootfitter foam to see what happens. I did that for two days, where I placed, moved, added, and subtracted different padding to my ankles to see what happened and what worked best.

Ultimately what worked best was to get the right boot, in the right size, fit by an outstanding boot fitter but the trial and error taught me a lot about what happens to my skiing with certain boot setups and it gave me insight into things to watch out for.

 

[JDV]

@JDV I imagine you thighs were also burning after a day of skiing too. A Lange 120 SC (Short cuff)? A good option of a boot since it is oen of the more upright boots on the market. Do you have the heel lift in these? A heel lift should open your ankle, not close it, it increases your range. The heel lift should also give a bit more room around your calf since it is rasing it out of the boot some. Do you have the spoiler removed? Has anyone flaired or cut down the cuff? While removing the spoiler and flairing the cuff that will help preventing your calf from pushing your leg forward too. Also, what binding are you in, does that have a high delta? Assuming at 5'2" you are in a fairly short boot this will be even more pronounced. As Mike says a gas pedal or a lift under the toe piece might help too.

@Philpug Thanks for the reply! Yes, I have a short cuff that has been ground down even further, no spoiler, liners that have been also opened up around the upper calf, 4th buckle been removed and placed so I have more room. I also have custom footbeds.

I don't have a heel lift in right now or a higher toe piece. I'm not sure if that will fix anything. I need more room in my ankle to flex. Heel lift is not going to help that - that is going to put even more stress on my knees.

This is why I was wondering about the Fischer vacuum boots - if the upper cuff could be shaped when heated then get a foam injected liner to help with my narrow heel and high volume calf.

 

[JDV]

Where are you?

Even though a heel lift would lift your calves out of the boot which would decrease the dorsiflexion problem, wouldn't it still tip you forward so you would be trading one problem for another and getting the same result?

What about an aftermarket liner where the cuff is heat moldable? I have the opposite problem (I need more forward lean), and when I molded my Intuitions (convection oven) for the third time the volume of the cuff decreased so dramatically I actually had to build it back up with a spoiler. I've also heard of other ways to decrease the volume in the intuition cuff (peeling and cutting out extra).

I also had a problem where a too long boot (it was an LV, so appropriate width) with a high volume liner around the ankle (so that it was buckled to only the first or second latch) caused my lower leg to have a more upright angle in comparison to a low volume liner buckled down tightly in the same boot. It seems as though when the ankle latch was tightened down with a low volume liner it pulled my ankle into the boot heel pocket so my leg was forced to mimic the geometry of the boot, but when a high volume liner was used my foot slid down relative to the heel pocket which forced a more upright lower leg.

I've also had my ankle padded in the past (I have narrow ankles and normal/large calves so it's historically been a problem) and when they pad behind the malleoli it pushes my leg forward and upright and when it's padded in front it pushes it back with more forward lean.

Most of these things were a nightmare for me, and they are not considered good bootfitting practices (and would decrease control because of increase in distance between foot and boot), but if you are miserable, maybe it's worth playing around with $5 bootfitter foam to see what happens. I did that for two days, where I placed, moved, added, and subtracted different padding to my ankles to see what happened and what worked best.

Ultimately what worked best was to get the right boot, in the right size, fit by an outstanding boot fitter but the trial and error taught me a lot about what happens to my skiing with certain boot setups and it gave me insight into things to watch out for.

@RuleMiHa

I am in Toronto. Not a ski town by any means.

I feel your pain with boot fitting. I am intensely jealous of people that go into a shop, try on a boot or 2 and off they go. I feel like it's a nightmare and I hate doing it! I'm a strong skier and most of the roomer boots on the market are WAY too soft for and the last is just huge. I also need lots of boot work done as well because of a half size foot difference. I've had a few local boot fitters scratching their heads trying to figure out what to do with me.

Where are you located? Do you have a good boot fitter? I'm willing to travel if it means happiness on skis this winter!

 

[Philpug]

@Philpug Thanks for the reply! Yes, I have a short cuff that has been ground down even further, no spoiler, liners that have been also opened up around the upper calf, 4th buckle been removed and placed so I have more room. I also have custom footbeds.

I don't have a heel lift in right now or a higher toe piece. I'm not sure if that will fix anything. I need more room in my ankle to flex. Heel lift is not going to help that - that is going to put even more stress on my knees.

This is why I was wondering about the Fischer vacuum boots - if the upper cuff could be shaped when heated then get a foam injected liner to help with my narrow heel and high volume calf.

Also, BSL are you in and what binding do you have? While the fischer IS an option, even with the ability to mold the cuff, you are not going to gain a siginificant amopunt of change over the very upright Lange. Actually the heel lift opens up the ankle allowing you more range. As far as working with yoru delta, something you can just try at home before you head to a shop. Do you have a full length mirror at home? Stand next to it a look at yourself from the side. Are your knees over the balls of the feet or out over the toe of the boot? If it is the latter, start by putting something under the toe of the boot that is about 1/4" thick, play with differnt heights and see how that feels standing there, and if it less stress on your knees and thighs?

 

[RuleMiHa]

@Philpug Thanks for the reply! Yes, I have a short cuff that has been ground down even further, no spoiler, liners that have been also opened up around the upper calf, 4th buckle been removed and placed so I have more room. I also have custom footbeds.

I don't have a heel lift in right now or a higher toe piece. I'm not sure if that will fix anything. I need more room in my ankle to flex. Heel lift is not going to help that - that is going to put even more stress on my knees.

This is why I was wondering about the Fischer vacuum boots - if the upper cuff could be shaped when heated then get a foam injected liner to help with my narrow heel and high volume calf.

But the heel lift could get your calf higher out of the boot so that a smaller circumference was being presented to the opening, and the toe piece lift could tip you back to compensate for the increased forward lean of the heel lift. Fixing different aspects of the problem simultaneously.

 

[Chris Geib]

Also, BSL are you in and what binding do you have? While the fischer IS an option, even with the ability to mold the cuff, you are not going to gain a siginificant amopunt of change over the very upright Lange. Actually the heel lift opens up the ankle allowing you more range. As far as working with yoru delta, something you can just try at home before you head to a shop. Do you have a full length mirror at home? Stand next to it a look at yourself from the side. Are your knees over the balls of the feet or out over the toe of the boot? If it is the latter, start by putting something under the toe of the boot that is about 1/4" thick, play with differnt heights and see how that feels standing there, and if it less stress on your knees and thighs?

To expand on Phil's excellent post:
Heel lift inside the boot & Toe lift outside the boot are two completely different things. One does not negate the other. You might need both to address the net-forward lean AND forward lean.

When you do the mirror test, don't forget your binding most likely has delta so also find out what that is and experiment with that much shim under your heel. In other words, if you desire toe lift, then just standing on a level floor you will already be better vs when you stand on your skis ...so test how your skis effect this once you click in. (You could just get into your bindings, but then those long skis act as crutches for you to lean on...)

To add to Phil's mirror test:
Can you flex & extend through a full range of motion while remaining in balance and cuff neutral?
Do you need shims under toe or heel to do so?

 

[Ktmdad]

Knee binding makes a lifter kit (4.5mm thick with the longer screws) that is shaped correctly to fit under the toe piece to affect delta---your dealer should be able to get them---the lifter doesn't eliminate all of the delta as there is a a 7mm diferential so you end up with 2.5mm.

Delta shouldn't exist---as you may know it came about when the manufacturers added brakes to the heel pieces.

Mike

PS: Playing with "Delta" is an effort to overcome an inappropriate "centered up position" caused by the combination of your calf circumference and your boots forward lean---so you could solve the problem a different way---by changing the boots forward lean, to position your torso correctly just ahead of the boot sole center, determined by your calf circumference. Bigger calf=less forward lean----skinny calf= more forward lean.

Ultimately you have to get the Tibia angle to the right position in order to have the stack of bones above oriented correctly---Tibia angle is affected by the boots forward lean and the size of you calf at the top of the liner.

Fore/aft balance can also be effected by the boot board angle and delta angle---tilting the boot (gas pedaling it) has a limited effect and teeters the boot, changing the effective forward lean of the tibia and moving load to the rear of the foot, it does work, but is limited.

According to the Knee documentation their standard delta with no lifter is 6mm. Using their 6mm lifter (which I use on my skis) you get a nice 0 delta. I ordered the lifter directly from Knee Binding and they urged me to at least keep some Delta but I strongly wanted to zero out the delta which also in my mind anyway every binding should be. Interestingly at least at that time almost a year ago when I ordered they didn't have the 30mm screws needed for mounting the toe piece with the 6mm lifter. Since I was using Binding Freedom inserts that require machine thread screws this wasn't an issue and I ordered the 30mm screws I needed in stainless steel from McMaster Carr (a goldmine for hardware).
Yes I drank the Knee Binding cool aid in hopes of keeping my good knees good but they also give you lots of options with toe lifts and canting shims to dial in your stance which is really nice IMO.

From their install manual:

The height of the KneeBinding heel platform is 32mm and the height of the toe platform is 26mm. This generates a fun and aggressive ramp “delta” of 6mm. Depending on the length of the boot sole, this will be in the range of 1 degree to 1.5 degrees. For skiers that want less ramp delta, KneeBinding offers lifter kits that raise the toe. For example, if you raise the toe 1.5mm, this makes the height of the toe 27.5mm instead of the default 26mm. The ramp delta is, therefore, now 4.5mm. If you add a 3mm lifter, the ramp delta will be 3mm.

KneeBinding offers standard lifter kits in 1.5mm, 3mm, 4.5mm, and 6mm. Each kit comes with two lifters (one for each toe) and the appropriate mounting screws.

The mounting kits that come with the Mist. and Core Models of KneeBindings

include 3.0mm lifters, along with the appropriate screws, so that when it is mounted, it will have a 3mm ramp delta. Naturally, these can be replaced with any other lifter kit (along with their correct screws) to achieve any desired ramp delta

Also this:

.Other Products
KneeBinding offers other products to make the skiing experience even safer and more enjoyable. Please contact KneeBinding to order any of the following products:

o Brake Kits – contain set of two brakes, any size.
o Lifter Kits – contain two toe lifters and appropriate screws
o Canting Kits – contain two heel plates and two toe plates. Each kit can be ordered

with IN-ward or OUT-ward canting in .5-degree increments (.5, 1.0, 1.5, 2.0, 2.5, or 3 degrees), combined with toe lift (1.5mm, 3.0mm, 4.5mm). Canting kits come with color-coded screws for ease of mounting. Please call KneeBinding directly for more information about canting kits.

o Plastic Templates – if you have skis that are too wide or too narrow for the standard mounting jig, KneeBinding can provide a reusable plastic template.

 

[PTskier]

Mike said:
"Delta shouldn't exist---as you may know it came about when the manufacturers added brakes to the heel pieces."

Hmmm.... I like how I ski with my Head PRX bindings and 8 mm of delta. I was on some Tyrolia Attack13 bindings with 4 mm, and I felt the lack of heel height. I shimmed the heels another 3 mm (1/8" Plexiglass), and I liked the result. Personal preference & individual body geometry.