Shape of the sidecut

[Guy]

I haven't done any math, but I would guess that neither circular, elliptical, or parabolic sidecuts actually contact the snow plane in a circular arc, nor that a shape could be made that would contact the snow plane in a circular arc at different edge angles (e.g. at both 30 and 70 degrees of inclination).

It would be interesting to choose a "most important" edge angle, like, say, for EC somewhere between 70 and 80 degrees, design a perfectly circular arc, and reverse engineer the exact sidecut shape and see what you get.

As Ken indicates, an issue probably much more significant than sidecut shape is the flexibility of the board versus the rider weight (and speed/centrifugal force), at a given board-to-snow angle. To take an extreme: if the board is perpendicular to the snow (never really happens), the middle of the board edge can never make contact with the snow (assuming an ice-flat surface), regardless of how much the board can be made to flex. There must be an optimum board-to-snow angle for a given flex and rider weight/speed, where the edge can make contact (with an even pressure) along the entire effective length. Therefore I suppose it's more important to match the rider with board flex in order to lay an extreme carve (board angle approaching 90 degrees). I would guess any deviation from a pure circular sidecut shape (which would definitely be the best shape at the other extreme of close to 0 degrees board-to-snow angle in order to get the perfectly circular board arc) is minor by comparison. And of course also significant is that the board is constructed to produce a good circular board arc when flexed during riding.

Alternatively, I've got some assumptions wrong here

Guy

[tufty]

Alternatively, I've got some assumptions wrong here

Not in my book. Both you and kjl are bang on.

Flexibility is a whole load more important, and flex profiles are vastly more complex than sidecut curve forms. The problem is that you can't see them. Or really sum them up in a way that makes for a good selling point. all you can do is try the board and say "I like it" or "I don't like it"

So expect "asymmetric front-biased progressive sidecut" to arrive (adspeak for "we fouled up horribly on this board, the sidecuts are neither centred nor the same on either side as the guy operating the machine had been drinking heavily").

Of course, this is all my opinion and I don't build boards.

Simon

[Pogokoenig]

Seriously, who cares about that?

I don't even know the Radii of my own Boards. I think the sidecut is important for carrying the board to a bar. With an elliptical sidecut and small radius it fits better into my hands.