realskiers

lannq:

I'm 5'11" and 200 lbs and ski with a DIN of 6-6.5 and haven't had a binding pre-release in several years.  I think newer "systems" are a lot better than older bindings flat-mounted.  For example, that last prelease was skiing pretty fast over frozen cat tracks and the ski just started vibrating enough that the boot came out on one of the reverse camber vibrations.  In fact, I'm not sure that the binding even released, but because the distance between toe and heel changed as the ski flexed and counter flexed, it just allowed the boot to come out.

There is plenty of research described on the Vermont Skier Safety web site that says that increasing DIN setting has little to do with what is commonly called a pre-release.  There is always anecdotal advice of opposing views.  Also a LOT of good information about how to fall so that you don't tear ACL's (this was taught to all Ski Patrol members 6-7 years ago).  There are also plenty of web posts about people being able to twist out of bindings with much higher DIN settings (12-14) while just standing still.  I don't see much difference between 6 and 8 if you decide to bump it up (but I'm not an expert and that's a personal opinion and you won't be able to get any money out of me even if you win your lawsuit    ). 

Technique may have a lot to do with it as well.  I don't know what "modern diagonal technique" is, but if you are balanced and riding the skis and not having to horse them around like in the old days, then not only is the load on the knees a lot less but the twisting load on the binding is a lot less as well.

What I decided to do was live with the DIN of 6 recommended by the charts until I had a problem, then I was going to use the Vermont skier safety site to analyze why it released (to see if increasing the DIN would help).  I haven't needed to do that.

Note, however, that a lot of the above is assuming that your iM72's came with the Railflex system, because that system is one that maintains a constant distance (and therefore pressure) between the heel and toe no matter how flexed or reverse flexed the ski is.  Like I said, a lot of the old "pre-releases" were actually because the ski reverse flexed (due to vibration or rebound) and the distance between the toe and the heel increased enough that the boot was no longer clamped in.  Binding may have still been locked down, but the boot wasn't there anymore.