This is slightly un/related:

http://www.wildsnow.com/379/backcountry-skiing-binding-flex-tests-updated-august-2006/

That's Lou Dawson's website. He has a lot of really detailed articles about binding tests and mods. When he does a "review" he takes the entire thing apart and inspects it first.

- BW




On Thu, Dec 31, 2009 at 7:33 AM, Allen Taylor <[log in to unmask]> wrote:
I messed around with the release tester at Cochran's. Its nothing too fancy, clamp the skis to a table, put an insert in the boot and click it into the binding. Then you use a torque wrench attached to the insert to release the binding and read the max torque. I only measured lateral toe release. The boot used was a Scarpa Skookum (vibram sole, 313mm BSL)

All measurements in Nm (Newton Meters)

Duke
Din/Torque
9/85
10/95
11/105
12/105 (repeated)
13/115

Dynafit Ft10 (10 din, lateral heel din set on 9)
toe lever position/release torque
down, ski mode/90
up, no clicks/120

Dynafit FT12 (12 din, lateral heel set on 9)
down, ski mode/90
up, no clicks/ 90,95
up, 1 click/150+ NO RELEASE

I guess all this really proves is that dynafit toes are variable in their release characteristics when the lever is up. This is not precise testing by any means either, I was applying force by hand and there is no way to tell if I applied the force the same way each time. I couldn't fit my praxis in the vice so I had to stand on them to do it and had a very different body position manipulating the torque wrench.

The numbers are scary, I hurt my knee last winter (no pop but stretched out the ligament enough the joint was loose and still feels lose sometimes) on my dukes with a toe din of 11 in a slow fall, according to this test an 11 din duke has much less retention than a dynafit with the lever up in some cases, 1 click in others.

I was going to just send this off to the FIS crew but I figured skiVT might be interested, I would like to see if anyone else (Shefftz?) has any input on this or has done any testing of their own. I still plan on ski mountaineering with the toes locked on my dynafits but I'm rethinking how I ski them in other situations. Then again they tend to fall off in ski mode when I hit stuff (hard objects under the snow). Also skiing in the woods with the levers up, the levers tend to catch on stuff and lock tighter. Looks like there is going to be a trade-off somewhere.

If I have time I might do a more in depth test so I can average out the anomalies. The other problem with the dynafits was when they released hard or not at all it pulled the toe out of alignment (generally 5 mm or so at the heel), which I assume if repeated will not be good for the bindings.

Allen

P.S.

Does anyone have a Carbon Fiber Tripod they want to sell me?
--
As lonely as the mountain can be, lonelier still is the man whose travels take him away from the mountains.

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