Alpine skiers can be surprised to learn that tech bindings essentially suspend your boot in the air above your ski. Your weight is not resting on the ski at all, but rather is supported by metal pins that insert into reinforced holes found on Dynafit compatible ski boots. It can be important to consider just how far off the deck your toes and heels are floating, since this can affect how your weight is balanced over your skis.
The height of the pins that hold your boots is not typically published by binding manufacturers. However this can be good information to know if you are trying to determine the angle of ramp between your ski and ski boot. As such, we took to measuring them. See below for a list of pin heights in millimeters for common tech bindings, accurate to within one millimeter:
|Binding||Toe Height||Heel Height||Delta|
|BD Helio 110||30||29.5||-0.5|
|BD Helio 145||30||30.5||+0.5|
|BD Helio 180||30||36.5||+6.5|
|BD Helio 200||30||36.5||+6.5|
|Dynafit Low Tech Race||28.5||28.5||-|
|Dynafit Radical ST/FT||35.5||50.5||+15|
|Dynafit Radical 2.0||38||51||+13|
|Dynafit Rotation 7||38||50.5||+12.5|
|Dynafit Rotation 10/12||38||51||+13|
|Dynafit Speed Turn||28.5||44||+15.5|
|Dynafit Speed Turn 2.0||29||45||+16|
|Dynafit Speed Radical||29||45||+16|
|Dynafit Speed Superlite||28.5||31||+2.5|
|Dynafit Superlite 2.0||28.5||36||+7.5|
|Dynafit TLT Expedition||28.5||31.5||+3|
|Dynafit Vertical ST||33.5||49.5||+16|
|La Sportiva RSR||28||28.5||+0.5|
|Plum 135 / 145||27.5||29.5||+2|
|RC1 by PG||24||30||+6|
|Ski Trab Gara Titan||31||30||-1|
|Ski Trab Titan Release||31||34||+3|
|Ski Trab Titan Adjustable||35.5||42.5||+7|
|Ski Trab TR Race||29.5||30||+0.5|
|Ski Trab TR Adjustable||29||35||+6|
|Ski Trab TR-2||36||44*||+8|
* Estimate of where heel pins would be.
The key number in the above table is pin height delta found in the last column. This number is an indication of how much higher your heel is than your toe. Higher deltas can shift your weight forward on the ski, which can be an unnatural feeling for some skiers. Somewhat counterintuitively, those skiers tend to end up in the “back seat” since their bodies naturally compensate with additional knee flex and backwards lean. While this is an OK position in certain situations, overall it causes poor control, unnecessary knee strain, and tired quads.
We would be remiss to not mention adjustment plates in this discussion. A tool for skiers with a quiver of boots, these plates are mounted under the toes (uncommon) and heels (common) of race bindings to provide some fore/aft adjustability. Since they are not zero inches thick, they will directly alter the pin heights of the bindings mounted on them. Here are the thicknesses of some popular adjustment plates, which are added to the binding pin heights:
Now before you go calculating millimeters and adding shims, take a step back to realize there is no “correct” pin height delta. Alpine ski racers are used to aggressive postures and tend to prefer driving from the front seat. Casual powder hounds often like their weight back a bit as they surf through fluff with their tips high. Cross-country skiers tend to prefer an upright stance, and don’t want to be nudged in any direction. Lou Dawson defined a baseline goal to be roughly +12mm delta based on early Dynafit binding models.
We think you shouldn't worry too much about a few millimeters. However skier balance is additionally affected by other variables, such as the forward lean of boot cuffs, ramp built into the boot sole, and stock or aftermarket insoles. If all of these variables point in the same direction, it is easy for your balance to get out of whack. This can often be a relatively straightforward fix that involves mounting shims or toe plates under your bindings. If you’re looking for advice on your particular setup, please send us a message.