Why Cant Your Ski Boots

[coupdevill]

If you put the thick side of the shim on the medial side then you're not actually aligning your stance. Instead you'll be leaving your alignment as is and flattening the ski to the slope. The reason you might want to reconsider this approach is that skiing is about balance. In order to achieve balance over a ski, the alignment should be of the pelvis' iliac crest and the center of knee mass over the 2nd met ray of the foot (effectively the seam of the boot). To achieve this in your current situation (as described) you would place the thick side of the shim on the lateral side to help bring your knee in. However, this is a bit of an oversimplification and really the best course of action is to visit a qualified boot fitter who understands actual stance alignment, not just flattening the ski angle. There are situations with bowlegged stances that require more of a hybrid approach, but it depends on the degree of your stance problem.

Good points, Fill the gap or straighten the leg, I always prefer straightening the leg (close to perpendicular from the ski), however if you ski with your legs underneath you and they rarely get to far away from your centerline, you probably like filling the gap, if you ski with a more modern style, letting the skis move away from your centerline then making the leg more perpendicular to the ski tends to be the choice. Try both, it will be very obvious which one you are.

coup

 

[Noodler]

Hence my "Dark Art" comment. So now I have two diametrically opposed fixes for the same problem!

I guess the only thing to do is try it one way then flip it over (I'm assuming these things are laterally symmetrical) I'm OK with all this ambiguity as long as doesn't shitcan my new boots in the process.

You can probably temporarily use a 1* shim without routering the boot toe lugs. What you can do is test the shims in both positions by doing one legged balancing drills (down the fall line and across the fall line) to determine which setup provides you with the better ability to balance.

 

[Fuller]

I'm heading up this afternoon for a few test runs and will report my findings.
Thanks

 

[David Chaus]

I have a similar issue, more bowlegged on my right leg than my left. I can get away without a canting shim on my left leg, however my right boot has a 2.5 degree Cantology shim to accommodate my right leg. And yes, I have a qualified bootfitter I have seen a number of times.

 

[Roundturns]

You can probably temporarily use a 1* shim without routering the boot toe lugs. What you can do is test the shims in both positions by doing one legged balancing drills (down the fall line and across the fall line) to determine which setup provides you with the better ability to balance.

Where can I locate the shims you use? Thanks

 

[James]

Hence my "Dark Art" comment. So now I have two diametrically opposed fixes for the same problem!

I guess the only thing to do is try it one way then flip it over (I'm assuming these things are laterally symmetrical) I'm OK with all this ambiguity as long as doesn't shitcan my new boots in the process.

Coup laid out a good case above. Don’t think you can always force the body into alignment.

Sounds like you have a leg length discrepency? Any cause discovered of the right hip/pelvis higher? Driving hours and hours with a wallet?

 

[Fuller]

Coup laid out a good case above. Don’t think you can always force the body into alignment.

Sounds like you have a leg length discrepency? Any cause discovered of the right hip/pelvis higher? Driving hours and hours with a wallet?

The report from the hill is that it worked pretty well and as planned. The first run felt a bit awkward / different at first - I noticed I was in a slight wedge and my stance was a bit wider than it normally is. The right foot inside edge was much more readily available though, so that part was good. The second run I narrowed up the stance width and tucked my heels back which cured the issues. Overall a significant improvement - I didn't bother to flop the shims to the other side. Maybe I'll do that tomorrow just to satisfy my curiosity.

Now to overthink it some more...

The lug isn't routed yet, does that mean that I currently have an additional 1mm of "leg length"? Would that extra length go away when the routing is done? I've never bothered to find out exactly how the interface between the boot and binding works. What actually sets the lateral plain of the ski, the top surface of the lug or something else?

Do I have a leg length discrepancy? I don't know but it wouldn't surprise me if I did. There could be more than one thing going on here.

James, there's no cause that I know of concerning the hip height but it's been there since I was a teenager. It's baked in for sure.

 

[Noodler]

Where can I locate the shims you use? Thanks

For temporary testing purposes we use the canting strips sold by Tognar.com (intended for under binding canting). They are cut into smaller pieces and then a small piece of duct tape is used to label the shim and provide a "handle" so that they can be held in place when stepping into the binding.

 

[Noodler]

The report from the hill is that it worked pretty well and as planned. The first run felt a bit awkward / different at first - I noticed I was in a slight wedge and my stance was a bit wider than it normally is. The right foot inside edge was much more readily available though, so that part was good. The second run I narrowed up the stance width and tucked my heels back which cured the issues. Overall a significant improvement - I didn't bother to flop the shims to the other side. Maybe I'll do that tomorrow just to satisfy my curiosity.

Now to overthink it some more...

The lug isn't routed yet, does that mean that I currently have an additional 1mm of "leg length"? Would that extra length go away when the routing is done? I've never bothered to find out exactly how the interface between the boot and binding works. What actually sets the lateral plain of the ski, the top surface of the lug or something else?

Do I have a leg length discrepancy? I don't know but it wouldn't surprise me if I did. There could be more than one thing going on here.

James, there's no cause that I know of concerning the hip height but it's been there since I was a teenager. It's baked in for sure.

Doesn't sound like you did any balance testing, just went skiing. If you're going to satisfy your curiosity, check out some of the information on how to test one-legged balance on-slope and do the drills to determine what is actually providing you with improved balance, not just what "feels' best when you ski like you always do.

 

[EricG]

check out some of the information on how to test one-legged balance on-slope and do the drills to determine what is actually providing you with improved balance,

2nd this.

i initially thought it was going to be time wasted, but as I stepped back to very mellow slope and truly focused, the difference was noticeable. The difficulty I had was finding a slope mellow enough early season that wasn’t too busy to actually do drills or the conditions were right to avoid frustration.

I used duct tape strips.

 

[Fuller]

Doesn't sound like you did any balance testing, just went skiing. If you're going to satisfy your curiosity, check out some of the information on how to test one-legged balance on-slope and do the drills to determine what is actually providing you with improved balance, not just what "feels' best when you ski like you always do.

If there is a particular balance test tutorial or methodology somewhere out there I'm not finding it, perhaps you have a link to something? I did spend most of my time on a super easy green trail doing slow easy turns on each leg in an attempt to gauge how the ski was interacting with the snow. You could call it an "up and over" drill I guess where you start on the little toe edge and let the ski roll on to the big toe edge to complete the turn. It's fairly easy to assess a difference if one is present from left to right.

 

[Uncle-A]

For temporary testing purposes we use the canting strips sold by Tognar.com (intended for under binding canting). They are cut into smaller pieces and then a small piece of duct tape is used to label the shim and provide a "handle" so that they can be held in place when stepping into the binding.

I would like to see how you are doing this if you have any pictures. I have used canting shims under the binding and it is the way I would like to have my skis done.

 

[Roundturns]

For temporary testing purposes we use the canting strips sold by Tognar.com (intended for under binding canting). They are cut into smaller pieces and then a small piece of duct tape is used to label the shim and provide a "handle" so that they can be held in place when stepping into the binding.

Thank you

 

[Fuller]

Well the results are in. I've tried the 1 degree shim in both directions and I didn't need to do a whole lot of scientific data collection to make a decision. It took about 30 seconds to determine that the concept of realigning my 69 year old physiology by shimming the little toe edge doesn't work. I was going to ski a few runs and do my "balance testing" but decided to flip it back while I was at the base lodge.

Substantial improvement by adding to the big toe edge.
Substantial detriment by adding to little toe edge.

Thanks for your help @coupdevill

 

[Phatboy64]

So I spent the morning reading through the whole thread, lots of good information, and conversation.
I have a question: what is the threshold/tolerance for how thin the toe/heal lugs can be routered down?
Meaning how thin is too thin?

 

[cem]

So I spent the morning reading through the whole thread, lots of good information, and conversation.
I have a question: what is the threshold/tolerance for how thin the toe/heal lugs can be routered down?
Meaning how thin is too thin?

the tolerances are determined by the binding norms (most boot fitters test and cut boots using iso 5355 soles) so the toe is 19mm the heel 30mm +/- 1mm any thinner and they wont fit into the binding correctly, (on world cup boots sometimes we add 3mm steel shims to the top of the lugs so we mill them 3mm less than the 19/30

the reason that Cantology only produce shims up to 2.5 degrees for some models is that they have hollow lugs so there is a risk of ending up cutting into a void space (fixable with the right glue and skills but it don't look pretty)

the reason 3 degrees is the norm for maximum outward canting and 2 degrees for inward canting is the amount of joint space at the knee.... even with those maximums some people cant tolerate the change so sometimes you have to set up "better than before" but not perfect top get the best results

 

[Uncle-A]

the tolerances are determined by the binding norms (most boot fitters test and cut boots using iso 5355 soles) so the toe is 19mm the heel 30mm +/- 1mm any thinner and they wont fit into the binding correctly, (on world cup boots sometimes we add 3mm steel shims to the top of the lugs so we mill them 3mm less than the 19/30

the reason that Cantology only produce shims up to 2.5 degrees for some models is that they have hollow lugs so there is a risk of ending up cutting into a void space (fixable with the right glue and skills but it don't look pretty)

the reason 3 degrees is the norm for maximum outward canting and 2 degrees for inward canting is the amount of joint space at the knee.... even with those maximums some people cant tolerate the change so sometimes you have to set up "better than before" but not perfect top get the best results

I was wondering what was done to the top of the toe and heel after one side of the boot gets ground down. How does it interface with one side of the toe at 19 and the other side is now less than 19 and one side of the heel is 30 and the other side is now less than 30?

 

[cem]

I was wondering what was done to the top of the toe and heel after one side of the boot gets ground down. How does it interface with one side of the toe at 19 and the other side is now less than 19 and one side of the heel is 30 and the other side is now less than 30?

when you are milling a solid soled boot it will be thinner than the norm so you add a lifter plate to it to make it over sized and then rout it back, when adding cantology wedges you have made the boot thicker than the norm so you rout it to bring it back to the correct size

so whatever you do to create the angle you increase the thickness and then cut back to norm

 

[Uncle-A]

when you are milling a solid soled boot it will be thinner than the norm so you add a lifter plate to it to make it over sized and then rout it back, when adding cantology wedges you have made the boot thicker than the norm so you rout it to bring it back to the correct size

so whatever you do to create the angle you increase the thickness and then cut back to norm

But in order to create an angle one side has to be thinner than the other?

 

[cem]

But in order to create an angle one side has to be thinner than the other?

yes you are milling one side down, you then ADD a lifter plate (normally 5mm) which makes everything too thick then the router cuts the top of the lug parallel to the bottom of it (which you have angled and added the lifter to)