Vicious anti-Dynafit slander

[yuckster]

Dynafit (and Silvretta) bindings release sideways at the heel, rather than the toe. Has anyone else noticed that it seems easier to twist out of these bindings than it is with something like a Fritschi?

For example, my chart (Type II) setting is DIN 6. On closing day at Killington, I had heel and toe both set at 6 (with the soft black springs included with the brakes). I was basically just standing on the piste, talking to my partner. I shuffled around a little clumsily, a little in the backseat, but nothing that would have caused me to fall under normal circumstances. But one boot pre-released laterally; I'm certain the culprit was the heelpiece rather than the toepiece because before I was able to click back in, I had to turn the heelpiece back to ski mode.

After clicking in again, I was able to easily replicate this form of release by standing on the ski and attempting to twist my heel sideways with the heel weighted and the tail edge of the skis engaged with the snow. I haven't done the same experiment recently with my other Fritschi setup, but that setup has been set at DIN 6 for a year or two without major problems (typically only releasing when I screw up and go over the handlebars, at least a little bit) and my memory says that it's probably a lot harder to force a release this way on a Fritschi.

My theory: it seems easier to generate torque around the femur than around the tibia/fibia, and this torque is applied to the heel first. If the heel is free to float rather than pinned, it's then easier to apply this force to the binding's release mechanism. The KneeBinding people have made the same claim.

Thoughts anyone? One doesn't want to increase release settings to a less safe level merely to compensate for a specific type of prerelease.

[PWDR8S]

Hmmmmmm, have to thiink on this one a little bit... http://www.techsourceconsultants.com/coppermine/albums/userpics/10020/chinscratch.gif

I know the situations you speak of and I have to jog my memory of incidents. I'll post more when I remember specifics.

Really good issue to discuss! Different binders have different effects.

[samthaman]

Thoughts anyone? One doesn't want to increase release settings to a less safe level merely to compensate for a specific type of prerelease.

your din is on 6. i don't know how much you weigh or how hard you ski, but i know that if mine was on six i could chop my ski into the ground and literally knock the ski right off my foot. I wouldn't worry about your knees at that setting, i'd be worried about losing skis and never finding them. I'd personally recommend you tighten them gradually until you stop having the problem. Those Din charts are designed by lawyers, and are consequently fairly conservative with their recommendations. For reference, I keep my touring skis on 9.5, my resort skis on 10, and the charging skis (see last tux tr) on 12 all the way around. If I'm in a high exposure spot i crank the fritschi's all the way to 12 as well. I consider these settings conservatively low compared to other people of similar weight/ability/ski-style, the charts however tell me I should be on a din of 8 (III, 175lbs, 6'1"), but i've found that an 8 causes almost comical pre-releases in even the the most mundane situation.

my $.02 - and to totally come clean, i'm not certified to adjust bindings or anything, but i do it a lot anyways:D good luck figuring this out.

[yuckster]

6'3"; 161lbs as of last measurement 6-9 months ago; boot sole 311mm. Generally conservative skier but sometimes ski psychotic speeds when there is plenty of room to turn on blue or black trails. Occasionally huck small features.

Fritschis have always been fine on 6. They may release easily, but when they have done so, I've always felt that the cause was driver error first and foremost. I'm comfortable with that setup even on no-fall terrain, as long as I'm comfortable with the terrain itself. It's not like I can easily make them prerelease just by lunging forward from a standstill.

[yuckster]

Also... I don't have a race background. Just a recreational skier who's gradually increased in technical ability over the years. Never made an honest carved turn until I got off of my recreational straight ski piece of crap setup in 2002-2004 or so.

Dawson claims, "most recreational backcountry skiers are type II" and I've never had a SERIOUS reason to doubt him until buying these Dynafits.

[PWDR8S]

I've had 5 heel releases with the dyna's since my pin issue a couple yrs ago.
I have them set at 7 and have not had any problems.... I release mostly due to operator error which is seldom. Heavy snow causes my ski to go one way and my boot the other and the other times was actual encounters with lumber or shrubbery in my path. I don't need to have binders cranked way up to make up for sloppy aggro skiing. I've been there, done that and value my knees more than the inconvenience of a drop. Let's see... 1 knee replacement = $thousands + time lost or ski equipment = maybe $1000 tops.... Hmmmmm... tough choice.

Do what works for you and protect your knees! I know too many friends now that have either lost the ability to ski or have exhorbitant medical bills and major life inconvenience due to time lost in rehab due to knee or leg damages from bindings set way too high.

Oh yeah...forgot to mention that I really suck at skiing. So ignore anything I might say. :)

[RR]

I guess I'm somewhere in the middle. I found that over the handlebars releases happened with my Freerides even when I was trying to save it. The DIN was 7.5 fore-and-aft on my Bum Knee side and 8+ fore-and-aft on my normal knee side.

That happened several times during drainage ditch crossings early in the season.

I bumped to 8.5 and 9+ and the problem went away. Been in some pucker inducing situations and found the bindings quite reliable...so far.

I will continue to strengthen the knee capsules support system....and take Sam's advice and slowly bump the DIN as my knees get more stable.

As for the Dynafits:

Seen some burly lines go very well on them....I suggest sending a note to jsheftz. He goes plenty hard in some interesting terrain and has been on various Dynafits over the years. I bet you find a setting and or mods that do the trick w/o risking your knees unduly.

[jshefftz]

We had this same conversation at the top of GoS #3, and my thoughts are:

-- Even if you are a Type II skier, terrain like GoS is automatically making anyone into a Type III skier (i.e., no matter how smooth or cautious your skiing intentions, anything that steep combined with snow conditions that variable means that the equivalent of Type III skier forces are being exerted upon the binding).

-- I weigh 145 lb (AT boots range from 296 to an effective 304, alpine downhill plugs are 305) and my release settings (lateral/vertical) are:
- 6.5/7 Dynafit
- 6.5/8 Diamir and non-race alpine downhill setups
- 7/9 SL race
- 7/10 GS race
- 10/13 SG/DH race (bindings *start* at 10!)

-- I have released twice from Dynafits in four seasons (and almost 700,000 cumulative vetical, with more still to come for this season of course):

- Ski (and boot, still have the bark mark on the boot tongue) got caught under a small horizontal log just barely hidden under the snow.

- Ski tip hooked on a small shrubby branch (just like hooking a tip in a SL race course).

Both times the binding released so quickly and cleanly that (combined with my not noticing the log/branch) at first I didn't even realize what had happened. ("Hey, what was that sound? And why am I on only one ski?")

-- I have never preleased in Dynafits, but I don't get any air.

[yuckster]

Thanks.

I'd already tightened up my DIN another notch after our conversation, and still had some prereleases. I'm going to bump the heel up another notch, to 6.5 before I go out this weekend, for sure.

Basically my point is that Dynafits don't seem to offer the same RETENTION at similar settings to traditional bindings, seems to be because of the ease of which a skier's body weight contributes to the heel pushing sideways... which can't happen in a traditional binding where the heel is always in one position. Release may require similar forces to traditional bindings when those forces are at simple angles like you see on the test bench, but retention is not as strong when those forces are at an atypical angle.

RELEASE in Dynafits sure seems reliable. They release damn easy at normal settings. At higher settings who knows... they might even release when you actually want them to!