MikeK wrote:If you look closely at the load path for those screws, it can be seen you'd really have to go far, far forward to put the load in a direction that would want to pull them out of the ski.
In the picture show, with the boot heel only raised slightly, they are loaded more or less in shear.
Knowing nothing about this mech, here is my thought. Skier is pounding the knee down very far, and most likely hitting some sort of stop (driving the spring solid or whatever) to lock up that rear mech. Then all the load is transferred to those screws, and mostly in tension as bar at the pivot would be very near vertical.
It doesn't seem to me that the part that hold that rubber bushing is too weak, it's perhaps it can't hold itself to the ski!
I think more screws would work but it seems to me the root of the problem is perhaps the binding doesn't have enough motion (or spring travel) for the style of skiing Harris is doing.
You could also look at redesigning that plate to help the front screws carry more load. Hint: that would mean stiffening the plate and moving the screw mounting point of the rear screws to make the pivot more in the center of screw pattern.
Mike, you are absolutely correct (well, mostly, and I'll elaborate in a minute).
The Meidjo has a lot more "duckbill feel" than the Rott Freerides, and that was the ultimate selling point for my use, and this is accomplished by where Pierre located that pivot location. And in my opinion/preference, that is what I really liked about how the binding skied; so to move that location forward would screw up how the binding skis. The Outlaw also has an aft pivot point (compared to the Rott's, which they (Rott) designed to be right at the tip of the toe, which some guys like, but I never did).
The above said, you are correct that the binding maxes-out spring travel and when it does it exerts tremendous upward (tension load) force on the two screws. But here is the thing on that; if you are just stylishly cruising corduroy or intermediate freshie runs (I personally alpine GS turn everything low angle to save my achey knees) and barely lifting the heel you would probably not run into a problem, however on steep bumped-out runs where you are deeling with sudden compressions, as well as routinely asking the skis to shut down and pivot turn 180 quick, you are going to drop knee deep. Knee on the ski deep? No. In old leather gear yes, and that is why we all used to sport kneepads (you could bang down deep and hit the top sheet not because you got splayed-out, and not so much because the boots toe-flexed so freely, but because you had near infinite ankle forward flex on your heel down ski, meaning the deeper the knee dropped, the more the downhill boot forward leaned. At least that was my style--I ski with a fairly tight tele split; my trailing ski is generally always at most a foot aft of the other. So that said, the forward flex of today's boots keeps me pretty upright (low is a relative term then), which I like from a power and knee-fatigue perspective, I don't even feel the need to wear knee pads anymore, and on that, it doesn't take too much to over-flex this binding, hitting the max spring range and yanking upward against the 2 screws. And a note: In the picture I'm hand flexing the boot in the binding, meaning I'm not putting much force on the flex, and the bellows aren't compressing.
22 Designs addresses the issue of travel by making its spring so long that it's containment tube barely clears the boot's heel. I have about 12 days skiing my Outlaws, even spring skiing banger bump runs and have never felt like I maxed out the travel. And as far as how they reconciled load distribution (concerning the afterward pivot point), the Outlaw uses a solid, one-piece heavy steel baseplate, anchored with 6 screws, and the lever load is transferred all the way though that plate aft to forward. In order to rip 22 Designs aft mount out, you would have to bend a rather unbendable 5" base-plate. IMO Pierre needs to make a low flexing, one-piece base plate (like .250" 7075-T6 or an .100"+ 301 1/2 hard (Stainless) that not only shackle anchors the second heel springs, but also sits under the forward part of the binding (in lue of the plastic piece). This would disperse the load far better throughout the mount. A fix I tried to come up with was a 1/4" aluminum plate that I milled to sit on the bracket (where it is held down by the screws, and it would've picked up another hole a half inch aft. That turned out to be a no-starter--the way Pierre designed the springbok it doesn't allow for the required clearance. The only way to strengthen this binding is to disperse the load forward. He also needs to increase the travel.
