So today I'm off the hill and wanting to drive this thread to a higher plane.
Having briefly suggested wedged stances for tight spaces (trees and lift mazes) in the true spirit of what I I want to expand on the movement itself. Opposing edge platforms turn the tips towards each other and the greater resistance to sliding that is a result of that stance can have a tactical plus much like toe in does in a car's front end. The pre-load keeps some tension in the suspension and makes quick turning response possible. Drift in the front end is also reduced. On skis it is quite common for some of this to occur since the skis swimming and drifting can be unnerving and using very slight corresponding edges would make the skis turn when going straight is the object. Is it an error to use opposing edge in this way? Not really once we understand the objective is to create some stability without creating a turn and the edge angle we're talking is minimal.
It's also worth considering that this is different from converging skis where one ski is completely disengaged. That particular example is more a racer move where starting the next turn by establishing the new platform will occur with an abrupt foot to foot weight transfer. I'm sure others here will recognize this as the classic converging step turn maneuver. Sadly, today we see many newer instructors doing a variation of this when trying to do an actual wedge turn where opposing edges are one of the elemental requirements. Telling them that is a movement error and incongruent with the fundamental requirements of the wedge maneuver often leads to resistance on their part. Even here at Epic I've seen what seems to be a thousand different threads blow up over this one little but very important detail.
Which leads us directly into the beginner corral part of this discussion and the how, when, what, and why of the classic wedge turn progression. It survives due to the student based desire to control acceleration, or in most cases fight that acceleration. The 3F's concept needs to considered quite valid here, Frozen students need a slightly offensive option before they will commit to moving and sliding across the snow. Fleeing students need that or they will quit and literally walk away from the lesson. Fighting students may not need that option as much but even they seem to benefit from some skid based speed control and a well done wedge is all about skidding. Compare that to a parallel turn progression that often is overwhelmingly offensive, especially during the acceleration phase of the turns where the skis skidding due to hockey stop like pivoting can become a big problem. A series of baby steps where a decreasing amount of braking that takes them from frozen in place to an offensive left tip to go left (offensive) end of the spectrum thus becomes possible. In that way the tactical objective of using braking from slight to moderate wedges and the skidding that involves makes sense and is why that progression survives.
But don't get me wrong here, I generally teach a parallel / diverging step progression as a default starting point. But it's a hybrid where converging steps and wedges are often an incidental outcome. I really don't get too hung up on that though since in that world accuracy in rotary movements is still an emerging skill set. So a wedge as the skis face the fall line followed by stepping across the hill, or wedging across the hill is no big thing. Nor is it a big thing if they start with a wedge entry until they gain the confidence to let go and do the left tip to go left stuff Barnes, Harb and so many others prescribe.
Finally I guess I should point out that while this post includes a ton of tactical information the mechanical underpinnings are absent. The mechanics of a wedge are pretty simple though and reaction forces coming up through the skis are acting in opposition, or enough so that the outcome is braking from the additional friction. Compared to a corresponding edge platform where less friction occurs we then have a clear spectrum of possibilities.
Edited by justanotherskipro - 3/14/14 at 2:18pm