G3 — Stomp Pad and ZED Binding Gaposis Breakage

This post sponsored by our publishing partner Cripple Creek Backcountry.

G3 ZED in downhill mode, showing stomp pad gap exceeding their now recommended 1.5 mm gap.

I’ve never been entirely convinced on the use of stomp pads with classic tech bindings such as G3 ZED. (Stomp pad being a block of material under the boot heel, with a small gap that closes up when the binding heel flexes downward under high loads).

A couple of reasons for my skepticism: Mainly, I knew that boot’s vary in shape, so getting the correct stomp pad height is difficult (leading to the dread medical condition known as “gaposis). More, stomp pads are a kludgy solution to inherent binding fragility.

I’d rather see a binding be strong enough, and not need the pad for all but the biggest, most aggressive skiers.

Thus, while doing my examinations of the G3 ZED, I gave a sagacious nod to the stomp pad, figuring “well, here we go again, but I’ll shut up and see what happens.” Apparently, what happened is indeed the ZED fixed-height stomp pad ran up against the reality that the ski touring boot industry doesn’t have much truck with the DIN-ISO standard for ski touring boots. (In my opinion a good thing, as we wouldn’t have the plethora of cool boots if they had to conform to 9523).

So, a guy breaks his ZEDs, ostensibly due to him not using the stomp pads. The breakage is published on an internet forum, and G3 discovers that indeed their stomp pad situation is problematic.

Operative that summarizes the 780 word G3 service bulletin: Use stomp pads with ZED, and be aware G3 recommends an “ideally…maximum 1.5 mm gap between the ski boot sole and ski brake or stomp pad when unweighted.”

Further, G3 states the following in their service bulletin:
“To address the potential scenario where non-conforming boots are used with the ZED binding, G3 has developed two additional stomp pad height options which will be available on December 19, 2018. The optional stomp pads will be 1.5 mm and 3.0 mm higher than the standard ZED stomp pad that has shipped with all currently available ZED bindings. These additional items should address any outstanding sizing needs at this time.”

Above is okay, though odd. If you examine the ISO standard, you’ll see it allows <>2 millimeters variance (latest version) in boot heel height. That means a boot could still be “norm” and exceed the 1.5 mm gap needed to make ZED reliable. Further, there is no norm or standard regarding the exact vertical position of the boot heel tech insert. Change the vertical position of the heel fitting, and the height of the boot heel changes while in downhill mode. In other words, a boot doesn’t have to be “non-conforming” to have dimensions that cause excessive gap above the original ZED stomp pad — because of allowed variation, as well as the position of the heel tech fitting NOT being part of the norm.

Further, the G3 communique states that “We were unaware there are many alpine touring ski boots in the market that do not conform to the recognized industrial norm for positioning tech inserts in their boots.” That’s a jaw dropper for me, as I thought it was common wisdom that boot dimensions are all over the map. But then, tracking the plethora of today’s ski touring boots is indeed a daunting proposition. Total sympathy from here, as I’m always overwhelmed with the explosion in touring gear options.

In my opinion ZED is still a player (though indeed being a first-year tech binding, which we never recommend) but be sure you configure the stomp pads correctly. I inferred from the bulletin that the ZED brake somehow doesn’t have the “gaposis” problem, but in my view you would want to be sure the gap between brake and boot sole was no more than 1.5 mm as well.

As always, kudos to G3 for dealing with this situation in their usual responsible fashion: upfront, open, a detailed bulletin. A product recall is unnecessary in this situation, but I’ll be expecting an adjustable height stomp pad to appear in ZED 1.2, perhaps similar to the adjustable “Freeride Spacer” ATK has come up with. ATK infos here.

I have to admit in getting a chuckle from this debacle. As I’ve been getting some flak about my credo: “avoid first-year tech bindings like the plague.” Well, here you go… Early adopters, check your stomp pads!

Historical note: This isn’t the first the heel height of non-norm boots, or norm conforming boots with the <>3 mm variance, caused binding problems. I recall a situation many years when a binding model’s brake did not work correctly with quite a few boot models, due to heel height issues. And I remember another time
some boots would not click into a binding due to heel height.