Dynafit toe pre-releasing

You can transition from skin to ski without taking off skis with brakes.  My new problem is spinning my downhill heel piece on steep, hard snow to lock down with the new dynafits.  Is there any way to spin those suckers with your pole?

I can do it on flat ground by putting my pole tip in the high riser when its flicked in off position. One side is easier to do than the other due to the 270 degree spin needed and your body getting in the way. It doesnt take much force so if you are torquing on anything hard you might not be doing it right. Havent tried it in more challenging conditions though.

Thanks Ron!

Edge, my boots are Axons as well, same size. Is your left boot by chance worse than your right?

Had a similar problem just a couple of weeks ago at Alpental.

I believe this is a property of the binding. Yes ice buildup etc. are all contributing factors, but my problem had none of those problems. Once it happened a second time (with what turned out to be a nasty impact on bullet proof snow, with a deep hip hematoma), I was wondering what the hell was going on. Under more controlled conditions, I was able to get it to happen real easy and actually see what was going on.

I had not skied that day. In fact all I did was carry some racing poles up the lift of the beginner's area and headed to the side of the hill where I was waiting for the group to come down, set the course and relieve me of the poles. It was fairly steep hard snow.

The first time I fell, the ski just de-edged and I was standing on a loose boot on the skit and caused me to slip. The second time I remembered that I was trying to kick (uphill side edge into the uphill) into the slope to make a bit more of a platform to stand on (waiting on edge is stressful) and that was going well until once the tip just popped out and then I went down hard onto the hip since it took both feet out from under me.

When I unloaded the gear and got to the bottom, I repeated the whole thing while watching very carefully. First, it takes very little torque to cause the "jaws" to open up. My guess is that normally, if this happens in skiing, the pin on one side is able to hold the ski in place until the torque lessens and the jaws shut close again. Also, under most circumstances and normal skiing, my guess is that there is not as much torque generated as one might think, especially in soft snow. In my case I was generating the lateral torque when kicking in, and also vertical tension or twist on the boot by being on the edge. Once the torque was released from the kick impact, the vertical tension probably tilted the boot enough to prevent the open side of the jaws to reclose into the pin hole. The side hill then caused the ski to go flat to the slope, twist out the back and I was down.

My guess is that if someone mounted a camera looking at the front end of a binding while skiing hard snow we would all have the heck scared out of us. From my experience, I would expect there to be an incredible amount of movement of the pins relative to boot, even so much as to at times, having only one pin holding the boot tip. But if this is the case, it may be that under those conditions, the force of the boot tip against that pin may be more than enough to retain the boot during those very short duration openings or partial openings.

Proper ski technique means that there should be considerable forward pressure from the lower leg, thereby pushing the toe of the boot down. When that happens the boot is actually assisting springs in the jaws to keep the jaws in a closed position. (If that is true, then you back seat skiers are at a greater risk of pre-releasing.)

Certainly, snow and ice packed into the pin holes can accentuate this problem, or alter the "engineered" performance to cause a problem. But my guess is that the only way to alter this is for stronger springs in the tip, or believe it or not to turn up the setting on the heel piece, which would take some of the rotation (torque) out of the boot. BUT, that is working against the design of the binding and could cost you dearly in other situations.

My son and I have skied Dynafit real hard for the last 5 years of so. In fact mostly at lift operations. I happen to be less aggressive a skier, but I weigh over 240lbs. My son is a lot lighter, but he skis very aggressively and drops jumps, chutes, you name it. Never blew out of these bindings except when I wanted to in a fall or iced holes. But we don't ski real hard conditions that much. Did hard snow last week and boy I have to say I had the thought on my mind as I was doing 50mph super g type turns. Wondered what would happen... Definitely load my tips!

Alan

Just reread my post, and it occurred to me that I have had pre-releases at unexpected times.   They have all been in deep heavy powder and some times with the tip a bit submerged with me correcting (getting into the back seat).

So, I would predict that sort of thing is happening.  I would predict that this binding is least predictable in heavy powder.  In that case the skier is more likely to be in a balanced weight position with less tip pressure.  During times where the skier may be forcing a turn at slow speeds, i.e. when just getting going or is too lazy to do a kick turn, or the skis are buried and you just want to get going.

(added comment) heavy snow at slow speeds. My guess is that there is not that much torque at cruising speed in any kind of powder.

Alan

"deep hip hematoma" the name of my next band LOL - nice write up and I know I read on some forum (tay, wildsnow, teton, powder) someone describing a repeatable deep snow release but with all the variables in deep snow it is hard to nail down. Was happy to read (well not) that you took the time like I did to investigate the cause of your hematoma and found that you could in fact repeat it. One real scary scenario I read was a guy screaming across variable hard snow and knuckled icy patches that had a dual release and a spectacular fall... twice in the same day. Luckly he wasn't injuried but he was confused until he discovered the likely cause through Lou's video. Doesn't change anything really but you idea of driving the ski and pressure the font binding has some merit.

"deep hip hematoma" the name of my next band LOL - nice write up and I know I read on some forum (tay, wildsnow, teton, powder) someone describing a repeatable deep snow release but with all the variables in deep snow it is hard to nail down.  Was happy to read (well not) that you took the time like I did to investigate the cause of your hematoma and found that you could in fact repeat it.  One real scary scenario I read was a guy screaming across variable hard snow and knuckled icy patches that had a dual release and a spectacular fall... twice in the same day.  Luckly he wasn't injuried but he was confused until he discovered the likely cause through Lou's video.  Doesn't change anything really but you idea of driving the ski and pressure the font binding has some merit.

you've convinced me! time to go to 5+ lb Dukes; can stomp all I want.

BTW, I've seen young dudes come screaming into ski lodges and just stomping to get out of their 16-din downhill bindings.

But until I switch to Dukes (or the new 4 lb $1,000 Dynafits), I'll just be careful to use boots with good dimples & soles, silicon the toe pins, dimples, heel pins, and heel shelf to reduce snow and ice build up,  and clear the dimples, toe piece, heel piece and brake of snow and ice before I click in, make sure the gap between my heel and the heel piece is precisely correct (I've had the heel piece move back on me over time and that has led to prereleases), I won't stomp hard on rock-hard ice or jump hard on rock-hard runnels and sastrugi, I'll tighten up my release setting a bit if I get unwanted releases, wear ski leashes on the steeps, and just hope I don't get a catastrophic release or pull my bindings off my skis.  I'm 225 lbs and have 5 pairs of Dynafits so I have to be careful even tho I ski like a geezer (geezers are more likely to get injured in a fall and take a longer time to recover than young bucks).

Oh, just read on another thread about incompatibility between tech fittings and rollers in Duke toe pieces! I guess that leaves the sometime-to-be released new Dynafits or Fritschis (or new boots, bindings, and skis for 15-20 lbs of new gear).