Gas pedalling

[Noodler]

Since it is impossible to determine what is right for a particular skier over the Internet, I would not attempt to do so.
It is worth clarifying what some of the modifications being discussed actually do.

Heel lifts decrease the amount of ankle flexion within the boot. They do not pitch you forward. The only time we heel lift (increase internal ramp angle) is in the case of limited dorsiflexion. Increasing ramp angle does not change knee flexion, it simply reduces ankle flexion inside the boot. This can lead to breaking at the waist. When measured digitally on a force plate people with limited dorsiflexion stand with an excess of weight on the ball of foot when in ski boots. A heel lift increases contact at the heel and actually takes weight off the ball and redistributes pressure to the rear foot. Again this is with limited dorsiflexion.

External toe lift (gas pedal) decreases knee flexion without changing ankle flexion. This tends to make the femur more vertical and moves the hips forward. We only toe lift boots if the skier has excessive knee flexion in a particular boot.

An internal heel lift and an external toe lift do two different things. One decreases ankle flex, the other decreases knee flexion.
They do not negate each other.

Ankles that are surgically fused are normally plantarflexed a couple of degrees, so you would select a boot that is as upright as possible and stiffer is better than softer. An increase in internal ramp angle would also be indicated. Keeping contact with the shin is very important so that whatever forward motion can be generated gets to the ski as soon as possible, since there isn't go to be very much.

Unfortunately none of this has taken into account the binding angle yet. This is why if I were in charge all bindings would be flat or easily adjustable. Because binding ramp varies with model and sole length it is a difficult variable. Not everyone has all the same bindings on all their skis.

Fore/aft balance is a very important aspect of ski boot set up and becomes more important as rom decreases.

pliny the elder

Nominated for "post of the month".

 

[Noodler]

Is it possible to raise your toe bindings as much as 15mm if necessary because that sounds like a lot? Or is there a max amount I can do before the binding no longer functions properly? I will say that I'm of the mindset where I rarely ever want my skis popping off so I've always skied with bindings at a DIN a fair amount above recommended. I only say that to acknowledge that I am aware of the risks of messing with your bindings but in reality, I'd be comfortable skiing if my boots were screwed on to my skis as I can't think of a single time in recent years where I wished my skis had released. Thanks for your help!

You are normally limited by the height of the original toe lug material on the boot. When you add material (the lift) to the underside of the toe, you must router the top of the lug to bring it back into ISO 5355 compliance. For the toe height this is 19mm +/- 1mm. There are ways to go "bigger" by adding a shim to the top of the toe lug like this (pretend this is a shot of the toe lug):

 

[Mike King]

I feel the heel lifts most certainly rotate me forward. The first day post-fusion of somewhat deep powder, 18" fresh on top of previous days fresh so pretty much bottomless, I was thankfully on the only pair of skis I own that has demo bindings and I could not get back enough to keep my tips up with the bindings mounted in the recommended (well behind centered position) I had to keep moving them back a centimeter at a time until I could keep the tips up and even then, I was having to push backwards the whole time like a leg press, to stay back enough since the heel lifts wanted to push me forward.

I'm a pretty decent skier but I admit that I don't have the lingo or the clear understanding of how to achieve proper balance or how one change effects another so that was just my experience but if I had moved my bindings forward or had even more heel lift, I would have been face planting from how extremely forward I was with the heel lifts. I do realize like in that video on balance that our body can do the opposite of what we think it would do to compensate and also realize it gets confusing when people are talking about being forward or back depending upon whether they are talking about the boots being rotated forward or back vs what the hips are doing in relation to that.

In your original post, you mentioned you were going out west this season. Where and when? The forum can probably identify a qualified boot fitter who would be able to balance and align your boots. These folk are usually pretty busy, so an appointment will likely be necessary. It also is not cheap, but it will be well worth it, IMHO.

Mike

 

[Noodler]

Imo getting heel lifts is almost always a bad idea. You don't want to be forward, you want to be centered. Heel lifts will put you forward and that will definitely suck in powder, because the weight is not distributed evenly along the length of the ski.

If you want the ski to turn easier, mount the bindings more forward. A ski does not react to the amount of shin pressure that is applied, it reacts to the position of your CoM along the length of the ski.

For years and years I was a "move the binding mount position" advocate, but after my testing last season on binding delta and recent revelations regarding mount position in relation to the ski's sidecut and flex, I am no longer a "move the binding first" proponent. I now know that I was using binding mount position as a poor substitute for what was, in reality, a fore/aft stance alignment issue due to the resultant boot and binding delta. Since resolving this delta concern by adjusting it with modifications to my boots and bindings, I have moved all my bindings to have my boot midsole centered over the narrowest point of the sidecut and the thickest point of the ski profile. Fore/aft is dialed in via delta adjustments only.

Delta adjustments are significantly harder to do and to do right, which is why I had avoided it for so long, but now I have seen the light...

 

[surfandski]

Just a thought (I’ve not read the entire thread) but have worked with a number of folks with fusions. I’d place heel lifts equal under both feet & then swap out the boot board from a rigid to a soft & perhaps soften further by drilling a couple holes in the forefoot on the fused side. This way you have an equal starting position & some capacity to ‘flex’.

*Not a BootGuy
**Have done this w clients in the past with good results.

That's a good point as I got the rubbery zepas in a previous pair of Langes and they are softer and the holes are a good idea. I'd swap those but they are a size smaller as I had to go up a size to a 28.5 after my fusion due to the cankle. I think I could go with 5-8mm shorter on my good ankle because once they removed all of the cartiladge in my fused ankle, I believe my lower leg is now about that much shorter or at least that's what the boot fitter I worked with last year thought.

Also, that's encouraging that you've worked with a number of people with fusions as I've yet to find a boot fitter that says they have experience with that. Man, I wish my Dr had fused it a few degrees further forward as I really think a few degrees would have made all the difference in my case. I thought I stressed how important skiing was in the equation but I guess he figured walking properly was more important, though I think a few degrees would have allowed for both.

 

[surfandski]

Just a thought (I’ve not read the entire thread) but have worked with a number of folks with fusions. I’d place heel lifts equal under both feet & then swap out the boot board from a rigid to a soft & perhaps soften further by drilling a couple holes in the forefoot on the fused side. This way you have an equal starting position & some capacity to ‘flex’.

*Not a BootGuy
**Have done this w clients in the past with good results.

That's a good point as I got the rubbery zepas in a previous pair of Langes and they are softer and the holes are a good idea. I'd swap those but they are a size smaller as I had to go up a size to a 28.5 after my fusion due to the cankle. I think I could go with 5-8mm shorter on my good ankle because once they removed all of the cartiladge in my fused ankle, I believe my lower leg is now about that much shorter or at least that's what the boot fitter I worked with last year thought.

Since it is impossible to determine what is right for a particular skier over the Internet, I would not attempt to do so.
It is worth clarifying what some of the modifications being discussed actually do.

Heel lifts decrease the amount of ankle flexion within the boot. They do not pitch you forward. The only time we heel lift (increase internal ramp angle) is in the case of limited dorsiflexion. Increasing ramp angle does not change knee flexion, it simply reduces ankle flexion inside the boot. This can lead to breaking at the waist. When measured digitally on a force plate people with limited dorsiflexion stand with an excess of weight on the ball of foot when in ski boots. A heel lift increases contact at the heel and actually takes weight off the ball and redistributes pressure to the rear foot. Again this is with limited dorsiflexion.

External toe lift (gas pedal) decreases knee flexion without changing ankle flexion. This tends to make the femur more vertical and moves the hips forward. We only toe lift boots if the skier has excessive knee flexion in a particular boot.

An internal heel lift and an external toe lift do two different things. One decreases ankle flex, the other decreases knee flexion.
They do not negate each other.

Ankles that are surgically fused are normally plantarflexed a couple of degrees, so you would select a boot that is as upright as possible and stiffer is better than softer. An increase in internal ramp angle would also be indicated. Keeping contact with the shin is very important so that whatever forward motion can be generated gets to the ski as soon as possible, since there isn't go to be very much.

Unfortunately none of this has taken into account the binding angle yet. This is why if I were in charge all bindings would be flat or easily adjustable. Because binding ramp varies with model and sole length it is a difficult variable. Not everyone has all the same bindings on all their skis.

Fore/aft balance is a very important aspect of ski boot set up and becomes more important as rom decreases.

pliny the elder

Wow, thanks for the great post! You all have been so helpful here as I admit I'm no expert, but the more I can understand, the better I can explain what I'm experiencing when skiing and experimenting to someone who is an expert.

I guess I understand what you are saying about the heel lifts not actually moving me forward but standing with your feet ramped vs flat, you sure feel like you want to fall forward unless making adjustments. Would it be the center of mass has moved? I just stacked some books on the floor and went from standing with my feet flat on the floor (very stable) to my heels on the books and there is a tendency to fall forward unless actively pushing your weight back which is very similar to how I feel when skiing in powder where I have to do leg presses to keep myself backwards (which is the opposite of how I've traditionally skied with a nice forward position, especially in the steeps), hence why I feel like the heel lifts are pushing me forward. I'm a flight instructor in many categories of aircraft and an A&P mechanic so I'm very familiar with fore/aft balance in a fixed object but I admit that the correlation of the ankle, knee and hip joints, along with all of the other variables like heel lifts, forward lean, ramp angles, delta.... makes this WAY more complex!

 

[surfandski]

In your original post, you mentioned you were going out west this season. Where and when? The forum can probably identify a qualified boot fitter who would be able to balance and align your boots. These folk are usually pretty busy, so an appointment will likely be necessary. It also is not cheap, but it will be well worth it, IMHO.

Mike

We'll be in Denver for a few days visiting friends at the beginning of January, then one week in Jackson Hole, one week in Big Sky, 3.5 weeks in SLC, then a week in Aspen and then a few more days in Denver before heading back to Florida the beginning of March. You can probably guess what pass we have......LOL

 

[Doug Briggs]

Nominated for "post of the month".

I'll second that.

@pliny the elder does a splendid job of quantifying the methods and mechanics that can come into play. His opening statement pretty much sums it all up, though.

Since it is impossible to determine what is right for a particular skier over the Internet, I would not attempt to do so.

You have to visit someone with all the knowledge he relates and let them actually see you, preferably skiing.

That said...

pretty darn good on groomers/spring corn and not bad in a couple inches of powder but as soon as it got deep like some 12-24" days on really steep terrain

Your words would suggest you are happy with your setup most of the time. Your issue appears to be only with deep, steep powder. That is not uncommon for people without biomechanical issues. Hence my suggestion of dorsiflexion that works with many people that I suggest it to. It is a adjustment of technique, not gear, and can be proven effective or discarded on the slope instantly.

I would be very reluctant to make boot/binding adjustments to an otherwise good setup without direct consultation from a pro with eyes on you.

Nota bene (again): I'm not a bootfitter.

 

[cantunamunch]

Is it possible to raise your toe bindings as much as 15mm if necessary because that sounds like a lot? Or is there a max amount I can do before the binding no longer functions properly? I will say that I'm of the mindset where I rarely ever want my skis popping off so I've always skied with bindings at a DIN a fair amount above recommended. I only say that to acknowledge that I am aware of the risks of messing with your bindings but in reality, I'd be comfortable skiing if my boots were screwed on to my skis as I can't think of a single time in recent years where I wished my skis had released. Thanks for your help!

I've skied with 14mm toe lift on DIY ramped lifters under the bindings - and I wouldn't recommend it to anyone. Very weird things happen: the boots feel stiffer, the skis feel _softer_ at that point than previously and the front/back balance point is very much not where you think it would be.

 

[surfandski]

I've skied with 14mm toe lift on DIY ramped lifters under the bindings - and I wouldn't recommend it to anyone. Very weird things happen: the boots feel stiffer, the skis feel _softer_ at that point than previously and the front/back balance point is very much not where you think it would be.

That does seem tall. That said, do you think it would have felt any different or better if you had tall heel lifts in?

 

[surfandski]

I'll second that.

@pliny the elder does a splendid job of quantifying the methods and mechanics that can come into play. His opening statement pretty much sums it all up, though.



You have to visit someone with all the knowledge he relates and let them actually see you, preferably skiing.

That said...



Your words would suggest you are happy with your setup most of the time. Your issue appears to be only with deep, steep powder. That is not uncommon for people without biomechanical issues. Hence my suggestion of dorsiflexion that works with many people that I suggest it to. It is a adjustment of technique, not gear, and can be proven effective or discarded on the slope instantly.

I would be very reluctant to make boot/binding adjustments to an otherwise good setup without direct consultation from a pro with eyes on you.

Nota bene (again): I'm not a bootfitter.

You may be right that it's not too far off (though I doubt many people would go with 20mm heel lifts if they didn't have to) since it doesn't seem too bad on firm snow but it also could be that my body just adapted to the wacky setup which wouldn't surprise me. I'll probably start by adding some 2-5mm shims under the toe of my boots in my bindings to see how that feels and take that info to a boot fitter.

 

[Brian Finch]

I've skied with 14mm toe lift on DIY ramped lifters under the bindings - and I wouldn't recommend it to anyone. Very weird things happen: the boots feel stiffer, the skis feel _softer_ at that point than previously and the front/back balance point is very much not where you think it would be.

I’ve done 10mm on the toe on a small boot & can confirm- the tails go awol.

 

[ScottB]

Surf,

As far as shims for your toes, do what I did. I put a plate under my binding toe piece, not under the toe of the boot. I unscrewed my binding from the ski, had a machined plate made to the shape and thickness I wanted, and then screwed the binding back onto the ski with longer screws that went through holes in the plate. In essence, i made a custom race plate for just my toe. That is what you want to do.You can make it any size you need. IF you want a picture I can post one.

As far as what your heels lifts do to your body position, it is complicated as a human body has lots of joints. Your body has one less joint, so what your body does is different than everyone's else's experience, at least on one side (or leg). then there is terminology misunderstandings. The bottom line for me, and I think you can take this to the bank, is your current setup puts too much weight on the front of your skis. I had the same problem with too much weight on my tips. I have full flex, but when I put a shim under my binding toe piece, it reduced the weight on my tips and my skis behaved properly. I expect it to do the same for you, although your fused ankle may affect the results (but I doubt it). With a plate under the binding, you can always remove it easily and go back to where you are now. You do have to get longer screws, which is not always easy to find because they are a custom screw that only ski binding use, but I found a low cost alternative with the same thread and larger heads. I ground down the heads and it worked fine. You can buy longer screws from some ski race shops, but they are expensive but a lot easier way to go.

 

[cantunamunch]

That does seem tall. That said, do you think it would have felt any different or better if you had tall heel lifts in?

IIRC I did have something in the 3-6mm range in the boots - and no. Heel lift in the boot can't change the boot cuff angle relative to the ski.

I originally responded to your OP upthread by noticing that shimming outside the boot at such drastic correction levels pretty much needs to be done in cooperation with a trained observer who can watch you ski and check your knee and hip angles. I deleted that post because it didn't seem connected to the rest of the discussion, but I'll put the observation back in here.

 

[Chris V.]

As far as shims for your toes, do what I did. I put a plate under my binding toe piece, not under the toe of the boot.

This is likely to be a better solution, because messing with boots is a mess under the best of circumstances, it's a permanent, one might say damaging boot modification, some boot designs just can't be modified in this way, raising bindings can be a do-it-yourself job while messing with boots certainly isn't, and it seems like every model of binding has a bit different ramp angle, so modifying boots might not even do the trick for multiple sets of skis.

Anyway, shimming the binding is what I have personally had done.

All of which assumes you've received qualified advice on what you, as an individual, need.

 

[surfandski]

Surf,

As far as shims for your toes, do what I did. I put a plate under my binding toe piece, not under the toe of the boot. I unscrewed my binding from the ski, had a machined plate made to the shape and thickness I wanted, and then screwed the binding back onto the ski with longer screws that went through holes in the plate. In essence, i made a custom race plate for just my toe. That is what you want to do.You can make it any size you need. IF you want a picture I can post one.

As far as what your heels lifts do to your body position, it is complicated as a human body has lots of joints. Your body has one less joint, so what your body does is different than everyone's else's experience, at least on one side (or leg). then there is terminology misunderstandings. The bottom line for me, and I think you can take this to the bank, is your current setup puts too much weight on the front of your skis. I had the same problem with too much weight on my tips. I have full flex, but when I put a shim under my binding toe piece, it reduced the weight on my tips and my skis behaved properly. I expect it to do the same for you, although your fused ankle may affect the results (but I doubt it). With a plate under the binding, you can always remove it easily and go back to where you are now. You do have to get longer screws, which is not always easy to find because they are a custom screw that only ski binding use, but I found a low cost alternative with the same thread and larger heads. I ground down the heads and it worked fine. You can buy longer screws from some ski race shops, but they are expensive but a lot easier way to go.

Thanks for that information. When I mentioned experimenting with shims under my boot, I meant some temporary pieces between the toe binding and boot so that I can quickly compare 3mm, 5mm etc. But once I figure out, or get close to the right height, then I'd like to do what you did with actual plates under the bindings. I'd love if you have some pics you could PM or post here and also your source for screws just to compare (what, drywall screws are no good?). Thanks!

Oh, and for the under boot experimenting, did I read somewhere that 5mm is as much as you can place between your binding and boot or could I go a little higher? Thanks everyone for all of the help! Hopefully I can experiment and then find a professional that can ski with me and fine tune me. Any suggestions betwen J Hole, Big Sky or SLC? SLC is probably the best setup as we'll be there 3.5 weeks.

 

[Brian Finch]

What bindings are you using? The Tyrolia/Head clamps will let you run shims up to 8mm with no issues. I have a bunch that I’m actually using to avoid boot out on my GripWalk’d SL skis.

 

[Noodler]

When it comes to getting the fore/aft stance dialed in, the challenge I ran into, for skiers with a quiver, is dealing with all those bindings on multiple pairs of skis. Different bindings often mean different deltas. Even the same binding released in different years can have different deltas. So I had to measure all of my skis' binding deltas and then take a hard look at what delta I could get most of them to in order to be consistent (+/- 0.5mm). This meant shimming under toes or removing mounting plates from under heels, etc. I found that I could get most of my skis set to 2.0mm delta (skis that I couldn't modify were either sold or no longer skied). Knowing that I had a consistent delta allowed me to then dial in the fore/aft balance via boot modifications. Gas pedaling can be done by adding a plate to the toe, but it can also be done by removing material from under the heel. I've used both, sometimes on the same boot.

 

[Mike King]

We'll be in Denver for a few days visiting friends at the beginning of January, then one week in Jackson Hole, one week in Big Sky, 3.5 weeks in SLC, then a week in Aspen and then a few more days in Denver before heading back to Florida the beginning of March. You can probably guess what pass we have......LOL

Try to schedule a visit to Jeff Bergeron (Boot Fixation inside Breck Sports) at the beginning of your trip. He does sometimes see people in Denver, although he may be so busy in January that you will need to drive up to Breckenridge to catch him. Another alternative is to drive to Vail and see Greg Hoffman (Ski Boot Fitting Inc.).

For either, it will be mandatory to setup an appointment well in advance. Figure out your schedule now and get something set up. A high quality pedorthists is what you need to assess your range of motion limitations and get the boots set to allow you to access biomechanics inputs you desire.

Mike

 

[surfandski]

What bindings are you using? The Tyrolia/Head clamps will let you run shims up to 8mm with no issues. I have a bunch that I’m actually using to avoid boot out on my GripWalk’d SL skis.

Salomon/Look Axial 3 and Tyrolia Attack. Thanks!