Tech boot BSL

[GPP33]

Is there a standard relationship across all boots/manufacturers between tech fitting spacing and "BSL". I have my paper template for my dynafits (thanks again bongora3) and I assume the BSL measurement is the conventional alpine BSL, not a special tech fitting BSL?

How is the BSL measured on boots like the dynafit Hoji which aren't compatible with alpine bindings and don't have a conventional BSL?

I know my tele bindings but this dark side stuff is mysterious.

[galibier_numero_un]

Are you concerned about running out of track adjustment range when switching between (say) a 26 Lange Freetour and a 25.5 Scarpa F1?

Is your concern with the rearward offset of the toe pin cups from the front lip of the boot? Most boots are about 15mm, but this is just one more reason for a test mount. Some templates mark both the toe and the pin line. Still, do a test mount.

Is your concern about finding the center of the boot if it's not marked - perhaps the influence of the missing lip on a boot like a Hoji on where the center of your foot is positioned?

... Thom

[GPP33]

I am looking at using different boots with the same (or within a reasonable range) BSL. I currently have Cochises but will probably add something more suitable for touring in the future. It looks like the likely candidates are close to my Cochise BSL so I'm not too worried about it, just got me thinking how they measure BSL is regards to tech fittings.

[Mofro261]

I am looking at using different boots with the same (or within a reasonable range) BSL. I currently have Cochises but will probably add something more suitable for touring in the future. It looks like the likely candidates are close to my Cochise BSL so I'm not too worried about it, just got me thinking how they measure BSL is regards to tech fittings.

BSL is really boot sole length regardless of the type of boot (or sole rocker); but clearly a boot without a lug in same size (26.0) will have a smaller BSL, ie ~300mm vs 280-5mm ish.

Whether you can use both with one mount depends on the range of travel of your binding.

[galibier_numero_un]

You can see on the order of a 15mm BSL difference on touring boots with the same mondo size.

... Thom

[GPP33]

BSL is really boot sole length regardless of the type of boot (or sole rocker); but clearly a boot without a lug in same size (26.0) will have a smaller BSL, ie ~300mm vs 280-5mm ish.

Whether you can use both with one mount depends on the range of travel of your binding.

That’s what I was wanting to know. So the “BSL” marking on the paper template may or may not line up when it comes to tech bindings.

You can see on the order of a 15mm BSL difference on touring boots with the same mondo size.

... Thom

This is why I started looking into it. Chances are I won’t end up with a boot without a toe lug on these skis, just got curious. If what mofro said is true then worrying about it before I have boots in hand seems pointless. I was thinking about erroring the mount toward one side of the adjustment or the other but I think I’ll just shoot for the middle.

[Mofro261]

That’s what I was wanting to know. So the “BSL” marking on the paper template may or may not line up when it comes to tech bindings.



This is why I started looking into it. Chances are I won’t end up with a boot without a toe lug on these skis, just got curious. If what mofro said is true then worrying about it before I have boots in hand seems pointless. I was thinking about erroring the mount toward one side of the adjustment or the other but I think I’ll just shoot for the middle.

I ski in boots that are mostly 25.5. And for most 25.5's, thats close to 295 mm. That is NOT foot size, ie 25.5 cm is the interior-ish size. I have tlt6 boots which have minimal lugs, I sized up to a 26.0 for width but that boot is a 287mm, staying in the the 25.5 the length is 277 and I would have needed to remount.

So, mount skis for the boots you have or want to get, and that BSL, or roll the dice and split the difference and hope whatever boot you choose fits in the adjustment range.

[galibier_numero_un]

I'd look a Evo's published BSL tables. As you've noted, you're going to find things clustered about both extremes for your foot size - the Scarpa F1 and other light/fast boots on the short side, and the Hawx/Technica/Lange at the other end of the scale.

You might try allowing for about 2/3 adjustment range in one direction or the other. It might work - or not. I once played this game but ended up with the next size shorter shell and missed dual compatibility by a mm ;-)

As far as boots with short toe lips are concerned, some companies move the Dynafit inserts back a bit for stride efficiency, and this further reduces the "BSL" from a mountng perspective (toe pin cup to heel insert distance).

... Thom

[waxoff]

Thanks OP, very interesting question. Ideally, tech fitting equipped boots should also be advertised with something like TFD, tech fitting distance. Or at least, toe tech fitting to virtual boot center distance. Where something like virtual boot center would be defined by where it would be if boot had iso toe and heel welts.

[XXX-er]

when ever I do a mount (almost always without a template) I locate the boot on the ski according to where I want boot center so I mark center on the boot with a sharpie or piece of masking tape and put a T square on the ski to line up the boot at ski center or wherever I want it in relation to ski center and I check the distance from tail in case the ski center marks are rong ... this is what is important

Take a tape measure and measure from the front of an AT or alpine shell to boot center & the rear of boot shell to the boot center mark, it will be the same cuz center of the boot is the center of the boot, I can't see a speed nose altering the boot center or the BSL measurement

yes the Hoji boot will have the pins slightly rearward of a non-speed nose AT boot but its the boot's position on the ski to ski center that is important IMO

so either the toe piece will be more foreward for normal or more rearward for Hoji by the distance of the difference of the pins if you wana care/geek out that much

[XavierD]

Boot sole length: the length of the boot sole. Not the length of the tech inserts, not the internal length. Don’t over think it.
If you didn’t mount your own fucking skis, the shop will use a jig for low tech bindings which goes off the inserts, not the boot sole. Sometimes tools help, and you can just pay your local ski shop.

[GPP33]

I thought everyone here mounted their own fucking skis. It’s not really a question of how to mount them, it’s a question of is there a defined relationship between BSL and tech fitting spacing and what the point is of even stating the BSL of a boot with no toe lug.

[I've seen black diamonds!]

Templates work on standard BSL, but some touring boots have toe inserts further back than others. Paper templates for tech bindings often have a mark for the pin line. Fiddle around with that and you'll have all the info you need.

[XXX-er]

I thought everyone here mounted their own fucking skis.

fuck i hope not

But how does that relationship matter as long as the boot center is correct ?

[Mofro261]

I thought everyone here mounted their own fucking skis. It’s not really a question of how to mount them, it’s a question of is there a defined relationship between BSL and tech fitting spacing and what the point is of even stating the BSL of a boot with no toe lug.

Ask yourself: does the toe pivot point alter where the center of boot is placed, or does the placement of the boot center dictate where the pins should be located?

If you cant answer that then yes please go to a ahop. Warning: they also need to know what boot you need them for.

[GPP33]

BSL is really boot sole length regardless of the type of boot (or sole rocker); but clearly a boot without a lug in same size (26.0) will have a smaller BSL, ie ~300mm vs 280-5mm ish.

Whether you can use both with one mount depends on the range of travel of your binding.

Thanks for all the “extra” advice but I really didn’t need help getting a boot centered. Just curious as to whether or not one can conclude that two boots with similar BSLs can fit in a tech binding as they will in an alpine binding.

[XXX-er]

then why did you ask such a stupid question ?

the answer is ... maybe

edit: if you know which 2 boots/bindings you wana combine you might encompass the 2 different BSL ?

[jackattack]

If you cant answer that then yes please go to a ahop. Warning: they also need to know what boot you need them for.

And for a tech binding, most reputable shops won't do the mount without the actual boot that is intended to be skied in the binding. The insert/pin interface is not always perfect and requires final adjustment before final tightening to ensure the boot is centered on the vertical plane perpendicular to the ski.

[reckless toboggan]

Okay.

Calm down.

There's a fucking mark on the bottom of the boot.

[gregL]

Thanks for all the “extra” advice but I really didn’t need help getting a boot centered. Just curious as to whether or not one can conclude that two boots with similar BSLs can fit in a tech binding as they will in an alpine binding.

Unless they are a Dynafit boot with "Speed Nose" or one of a few Scarpa boots (early F1 and F3, for example) when they shortened the distance between the tip of the toe lug and the inserts, they will be remarkable similar.

Edit to add: After thinking about it, I believe Scarpa moved the inserts further away from the toe for a couple years to get the pivot point closer to the ball of the foot - I think I had F1, F3 and Spirit 3 boots that came this way. I believe they were ~15mm from the tip of the toe lug rather than ~12mm.

[reckless toboggan]

Mount the toe piece of your pin binding for the marked center on the bottom of your rando touring boot (with the shorter bsl) on the recommended mount line of the ski.

Then adjust the heel track of your pin binding for your longer bsl at/alpine boot, which puts the center of that boot 0 to 10 mm back of the line on the ski.

It will ski fine.

It will all work out.

You are okay.

Lucky Strike. It's toasted.

[hafjell]

Mount the toe piece of your pin binding for the marked center on the bottom of your rando touring boot (with the shorter bsl) on the recommended mount line of the ski.

Then adjust the heel track of your pin binding for your longer bsl at/alpine boot, which puts the center of that boot 0 to 10 mm back of the line on the ski.

It will ski fine.

It will all work out.

You are okay.

Lucky Strike. It's toasted.

Thanks. I needed that.