Nasty pre-release on Dynafits...

[chamonix]

I thought I would consult the collective for ideas, why I took a hi-speed crash today..

I had a nasty "pre-release" with Vertical STs, (with brakes) on my new Nunataq skis today. I have been slowly ramping up my speed, skiing hard pack snow, in big carving turns for the last few days. Really like the ski, too. Boots are Scarpa Rush.

End of day, I went up the tram at JP (first clue?) then stepped out side to put skis on. When I put on the binding I carefully check for snow/ice buildup under the toe mechanism. Snap it closed and open a few times if needed. Then I engage the pincers, and before I stomp the heel I swing the ski back and forth a bit to clear out the cups.

Well after cruising a narrow tree lined chute, the run opens up and I picked up more speed. Smooth groomed surface, this run had just opened to skiers. No real bumps to speak of.
Suddenly BAM one ski popped off, followed by the other. I slammed down on my hip, and tore a big chunk out of my helmet when the integral visor hit the hard snow and tore off.

So what happened? When I tried to put the skiis back on, as soon as I weighted the ski (icy side slope) and started to ski down it kicked right off again. It wasn't like that at the top of the mountain.
Finally I had to lock out both toes to ski the next steep pitch. Later on the lower sections I went back to ski mode at the toes. No problem.
I still don't understand what happened,
a/ why the ski popped off
b/ why I couldn't get EITHER ski to stay on, after the fall.

I have consulted the WildSnow pages on Dynafit setup, have DIN #7 on both lateral and vertical release values. Shim spacing is good.

Any ideas? It is scary to ski a binding that suddenly just "lets go" at high speed.

helmet damage; this was a hard hit...

I guess I should have been on teles..no release= no falls.

[Sheik Yerbouti]

Earn your turns! Riding lifts is bad karma. (sorta kidding) Check your local dealer first, if you get a good answer there keep us informed.

[lowangle al]

The 2 times I hit my head skiing was because of a binding malfunction. Having a ski pop off sucks

[wooley12]

They are mysterious devils these Dynafits. Assuming that the new mount is proper, my guess is that you still had some ice in the toe cups even after you swung them back and forth to clear them. After a couple of years in Comforts and ST's I have had only one pre release when I was skiing the frozen (0 deg day) corduroy at Sunday River. The toe just stepped out of the binding as I turned to a stop. I have heard that on some boots the Vibram sole may need a little shave to sit properly in the toe.

[chamonix]

thanks Wooley. I think you may be right, about residual ice in the toe cups, though I did swing each ski back and forth a few times.

It still sucks when a binding releases (at high speed) for no good reason. A little earlier on this run , where the trail was narrow, if the ski had come off I could have slid/tumbled into trees.


Maybe the answer is this binding?

new G3 binding, but it won't be available for a while

[Sheik Yerbouti]

I'm hoping the Ion is available for Demo at the Outdoor Retailer show in a couple of weeks, would love to try them on and make a few turns.

[Greg]

Yep, the solution is new bindings and skis. Just send me your current ****ty setup.

Seriously, like people said above, probably some ice in the cups or in the toe mechanism. And seriously, you can send me those skis.

[chamonix]

Greg,
I like the skis.. I do check the toe mechanism for snow build up, know where it can pack in; I had Comforts back in 2006... I just don't trust these new bindings for the moment. I also have Verticals on my Tonics, ski with the same boots, no problem ever.

My hip is starting to hurt from the fall..

[Dostie]

My hip is starting to hurt from the fall..

Bummer. Major.

Every time I've had a premature release, or saw a friend having that trouble, it always seems like it was some ice that didn't get completely worked out that was causing the issue. But in each of those cases, it was not evident and we did the proper Dynawiggle with the toe too. And then the next time it wasn't there. Perplexing but the issue always went away. It sure messes with your confidence though.

[dschane]

A friend and Dynafiddler always carried a handmade tool, basically a portion of a metal wire hanger and he used the tip to scrape ice out of those cups. I lack Dynafit experience to know, but it seemed to work for him.

[Quadzilla]

Scarpa Boots, I would check the clearance between the soles and the arms of the toe unit. If it is close and a little ice on the soles then you could pressure the arm and disenage the fronts, Or, the clearance is wrong between the rear pins and the boots. Or, you found out why Dynafits make lousy resort bindings. They suck on hard pack........

[Greg]

Ice on the soles could be the culprit. Was the snow sticky that day. Sometimes I find that when snow sticks to the sole of my boot under the toe, the binding toe unit "wings" will not engage all the way, btu maybe enough to make you think they are engaged all the way. Odd that it happened on both boots though.

Dynafits are lousy resort bindings, but sometimes they have to be used that way. I do a lot of sidecountry skiing that requires some long fast groomed runs getting to and from. I try to take it easy on those, although my partners are not always accommodating. Last week I was skiing with a friend - former masters national champ in downhill I think - who was on the vert/nunataq setup and he was flying. I scared myself silly trying to keep up with my old Voile Insanes that have not seen a file since, well ever. Has sort of got me thinking it might be time for a tune.

[DFur]

Funny, I’m having a very similar sounding problem. I bought a brand new pair of Radical ST’s for a new rig this year, which are mated with new Dynafit mercury boots. I had them mounted at a local shop that does good work. First trip out I stepped into the bindings just like normal, hinged my knee a couple times to make sure the pins were seated/no ice, and clicked the heel in, took literally one STEP and came out of both bindings AT THE TOE! Release tension was set at 7, but felt more like a weak ZERO. I fiddled and couldn’t get them to work, so I retreated to my old skis. Took them to the shop, they checked sole length and said that could be an option, that they had been set for an older-style of the same binding and possibly that could contribute. Next trip out I started easy, they seemed OK, but on the first turn—on firm but smooth snow at low speed—the binding released again. I had to lock out the toes to get down. Back to shop, used the torqe thingy on them, etc, checked all the parts, springs, etc and we cannot figure out what is wrong. If anyone has ideas I’m all ears—been inside and out on these and cant find anything amiss yet they simply aren’t working.

[Quadzilla]

Interesting, IME, Dynafit bindings mated with Dynafit boots is a solid setup compared to Dynafit bindings mated to other brand boots. Rereading the OP's first post, maybe while riding the Tram the boots heated up and got wet, then stepping outside they froze immediately, soles loaded up with ice and compromised the fit. Maybe same problem with DFur. Ultra cold temps causing ice on soles where you wouldn't look. Getting back to my original statement, Dynafits are great BC bindings, but fickle and unpredictable resort skiing, more so on groomers. The bindings don't float and dissipate the loads so you need to back off or...........

[chamonix]

Greg and everyone thanks for these ideas. I agree that Dynafits are lousy resort bindings. But they will work on smooth groomers, and I wanted time on this setup for an Avy course and skiing at Rogers Pass later this month. I might even ski them at Revelstoke for a day or two (less likely now!).
It may just be that after the first, high speed release, it was only the left ski that wouldn't stay on, then I decided to lock out both toes to ski down the rest of the run. But putting the skis back on (after the fall) as soon as I weighted the skis, the left one (then the right) kept kicking off.
I mentioned I had skied a steep, icy chute before this run opened up. When I stopped to wait for friends, I noticed I had had trouble loading the ski tips. I checked, and my boots were still in walk mode. So before I skied off again, I locked the cuffs forward. A few seconds latter, the left ski popped off at high speed. So maybe the left ski forward release value was set too light, but I could ski it safely in walk mode ? I checked all the release settings again, and the numbers still look good. I cranked everything up from a DIN 7 to DIN 8. Maybe, getting off the Tram I had some ice form in the left boot heel pin receptacle and stepping in the heel pins weren't fully seated?

the Nunataq's were fine at speed BTW, no tip wandering or chatter. Another great Volkl ski , even for such a lightweight design.