@ Neonorchid: Here are answers to your 3 good questions:
1) Yes. Good idea. I have 4 cords coming down from the ceiling — but not everyone has this luxury ... so I removed them from the images and from my description. But yes, if one can do this, go for it.
2) There is no appreciable lateral movement of the boot with this set-up: I've been utilizing this rig for some time .... and it's dialed-in. Even if there was lateral movement of the boot — respectfully — so what? This set-up addresses peak-release, not force-displacement or torque-rotation. Only the peak-release is 'measured', so some movement is — respectfully — irrelevant.
3) The toe-piece serves as the means to make the measurement. All toes are force-imparting devices. The boot has a certain length (it has its own lever-arm) and both the toe-cup and the heel-cup form 'virtual pivots', about which pivots the unconstrained ski can selectively hunt in order to satisfy Enrico Fermi's basic concept of entropy (the system hunts to which ever virtual pivot provides the lowest path to release). The toe, in concert together with the boot's lever-arm and the ski's virtual hunting, form a torque wrench. That's why one should not re-adjust the already-adjusted toe piece in order to have this test provide meaningful information.
(( If one wanted to measure torque with this set-up, it's easy to do: weld a 1/2-inch socket to a binding mounting template that has turnbuckle-locking plates (to rigidly affix the template to the underside of the ski); then position the socket directly "over' whichever virtual pivot you desire and lock the template. You could position the socket directly over the toe-cup's virtual pivot to measure the peak torque supplied by the combination of the lateral heel mechanism's peak-force and the boot's effective-lever-arm from the heel to the toe's virtual pivot; and/or, you could position the socket directly 'over' the heel cup's virtual pivot to measure the peak torque supplied by the toe mechanism's peak-force in concert with the boot's effective-lever-arm from the toe to the heel's virtual pivot. But it's not necessary to measure a torque value. It's easier to measure the distance from the projected axis of the tibia to the two points noted (above) at 40 cm aft of the tibia and 50 cm aft of the tibia, then validate whether there is a lateral toe release or a lateral heel release at those two points on the afterbody of the ski, as noted above. A measuring tape is less expensive than a special socket-mounted template plus a torque wrench. ))
@ Eagles Pdx: As I have shown in the graph that I have previously posted (twice) that plots "Release as a Function of Retention" — Pre-release is NOT correlated to DIN's. DIN's = release. Retention (anti-pre-release) = unique (non-standardized) features of each individual binding design. Release adjustment settings do not correlate to retention (to anti-pre-release). Respectfully, I don't know how to be more clear about that point (sorry, sincerely) ...
@ Philpug: Yes, very good idea (sincerely). Could you pls start a new thread that polls skiers something along following:
Approx how many skier-days do you experience between each toe pre-release ?
Approx how many skier-days do you experience between each forward heel pre-release (heel is found open) ?
Approx how many skier-days do you experience between each forward-pressure-related heel pre-release (heel cup is found closed) pre-release ?
Approx how many skier-days do you experience between each lateral heel release pre-release (noting that it's difficult to distinguish the mode) ?
When you had a release, are you sure it was an unnecessary pre-release or might it have prevented injury (a necessary release) ?
Regarding the previous question, how could you know / how could you tell the difference ?
What brand / model of bindings were you utilizing during those cumulative skier-days ?
Do you think skier error and / or certain terrain may have precipitated each given pre-release ?
Approx speed at moment of pre-release ?
Did the pre-release occur while landing a jump ?
Stiffness of skis and boots ?
Ski length; boot sole length (cm) ?
Status of ski-tuning ?
Gender ( m / f ) ?
Height; weight; age; skiing-style; recommended DIN ; actual DIN: ( toe lateral; toe vertical ( ! ); forward heel; lateral heel ) ?
Snow conditions / temperature ?
Visual conditions ( fog, sun, flat-light, etc ) ?
Was there 'excessive' snow, mud, ice, bubble-gum, tar or other foreign matter between the sole of your boots and the bindings?
Is the forward pressure of your bindings correctly adjusted per the manufacturer's recommendations?
How frequently is the heel track of your bindings degreased, cleaned and re-lubricated (if relubrication is specified) ?
How worn are your boot soles; AFD's; heel pads ?
How often are your bindings exposed to road-salt or race course maintenance salt ?
Are your boot and your bindings (both) 'TÜV-Approved' (see manufacturers' information) according to ISO 5355 (boots) and ISO 9462, 9463 and 11087 (bindings)?
How effective are the recentering characteristics of your binding (lateral toe, forward heel, lateral heel) ?
If you have a toe-height adjustment, is it correctly positioned ?
When was the last time your bindings were fully-inspected and tested by qualified / certified binding technicians at a ski shop ?
Can the treadle of your brake freely-move 'below' the top-surface of the heel-pad during ski counter-flex to prevent the heel from being pried-open ?
Are all of your binding's pivot-points (lateral toe; vertical toe; forward heel; lateral heel) located 'off-axis' from the compressive forces generated by the non-compressible boot sole during normal ski flex ?
Can you 'self-release' from your bindings in each mode of release ?
Do you have cants, shims or tape on your boot soles that cause the soles to deviate from the standard dimensions and coefficient of friction specified for alpine boot soles according to ISO 5355 ?
Do you have tape on top of your AFD's or heel pads ?
How many days of skiing did you have within the season of skiing in which the pre-release occurred, prior to the pre-release ?
What injuries were sustained as a consequence of the pre-release ?
Did you know that a special new dynamic impact test (proprietary to Howell™ Ski Binding company) can measure the 'effective-retention' of your heel piece?
After pre-release — did you visit a ski shop for troubleshooting-action; change binding brands; re-adjust settings; soften boot flex; upgrade your eyewear prescription; take a lesson; leave everything the way it was ... / ... ?
Howell™ Ski Bindings
Edited by Richard Howell - 2/25/13 at 6:48am