Originally Posted by HeluvaSkier
Your comment on how base edge bevel can effect radius (because you have to tip more with a higher base bevel) is very interesting to me. I have never really thought about it, but it does make sense. I have always looked at it in terms of a 1.5 base required that the edge would catch very late in the turn, load quickly and release. This almost unilaterally means that the skier is going to travel a straighter line for much longer than usual...
I would agree, for PSIMAN.
I see the turn shape as being more dependent on intent
than on the net angle of the edge to the snow. In other words, in any real life situation it is impossible to keep the angular acceleration of the skier's knee to anything like a constant. So, given a greater base bevel, the skier would be required or tempted to accelerate the knee more within the same elapsed time and travel distance.
Notice then, that that also means greater deceleration of the knee to modulate the ski camber once the edge is engaged.
Is it possible, then, that 0.5 base allows a more delicate touch at the early part of the turn, partly because the deceleration of arrival is less?
Whygimf's last sentence sort of relates to this but I haven't worked out how yet.
As to Atomicman's concerns with inaccuracies. Certainly it is a problem. Especially with hand tools that only engage a file's width of an edge at any given time.
I posted this to DC ski some time ago, when I first started thinking about this problem:
|Let us consider the bottom of the core as a standard plane of reference. Ideally, the base should be of a given thickness relative to this. The edges are fastened directly to this plane. They are the hardest thing on the ski. They therefore provide the best guide short of sonar, magnetic resonance or other non-destructive probing of where exactly the core is under all that black plastic.
So, short of all those probing methods, a median height between the edges is assumed to be reasonably parallel to the core. We then set the edges relative to that median.
Could this be substantially off? I suppose it could, if one edge was -substantially- and -consistently- (tip to tail). higher than the other.
What, then, is the prime mechanism making sure neither we nor the shop unwittingly build in 1-3 degrees of cant (tilt in the roll plane), wreaking havoc on our knees and hips?
I don't know- haven't thought about it, or the similar problem of misaligned binding bridges for stone grinding.
I suspect that the answer is in the "consistently" part. Since all our tools deal with only a little section of ski length at a time, we are more likely to notice mistakes as apparent "twist" in the result.
EDIT: I am no longer convinced that the above base thickness/base grind error is the only possible source of consistent off-bevel.
Longevity: Just to clarify, my original question was whether there is any 'protection' from the base to a 1/3 as opposed to a .5/2.5 say. It relates to the acceleration/deceleration argument above.