Just wrapped up my 8th day in a row of...
Just wrapped up my 8th day in a row of skiing, all at resort with my new coombacks mounted w/these dynafits. I have some concerns about the binding but it may be a function of operator error and/or something w/mounting. the toe piece on my right ski has pre-released several times this week, once at very high speed. the brake mechanism also popped off in that same crash. My only explanation for the toe pre-releasing is possibly some snow/ice build up underneath. I know big mountain guides, heli guys, vert b/c skiers use this binding so I know i'm not pushing it beyond its limits. Sandy, any ideas?
I'd also lean towards snow or ice buildup for the pre-release. Its best to cycle the toe mechanism a time or two before stepping in using your pole, that tends to break up most snow or ice under it. Then step in to the toe piece but before you step into the heel lift your foot a time or two which rotates the ski up and down and then the cutting grooves on the toe pins clear any snow or ice in the pin holes on your boots, then step down on the heel and you should be good to go.
John, Arthur is right on target about clearing the toe piece and rotating your boot in the pins. Other things to check: proper DIN setting, proper forward pressure (the Dynafit "spacer" should fit btw boot and heel piece, but should be a bit stiff to pull out). Only a few mm either way can mess with your release. I'm not sure about the brake coming off. Possibly check all screws for tightness, etc.
I'd like to add to this here, Sandy and Arthur are spot on on this, but here is another tip...
When I step the toe piece in I pick the whole ski up and "wag" it back and forth a few times (just like twice) then I step down into the heel piece. This helps to ensure that both toe grommets (holes) are set correctly and that one it's just a hair or two off. Does that make sense?
I had the same problem, with my Coombas "chattering" on ice, then one ski (Vertical ST) would occasionally release. Found this excellent article, and realized one ski release value was set too light. Here is a series of illustrations on how to adjust the DIN setting..