Why are kneeboards so wide?

[NomasTomas]

I have a lot of experience shaping, but not a lot of experience shaping kneeboards. Consensus dimensions seem to be 5'11" x 23-1/2" x 2-7/8" in either a swallow-tail or round-pin outline. I understand the length and thickness dims, but I'm curious about the width. My kneeboard is 5-11 x 23" x 2-1/2" 38L. A comfortable "stance" for me on my kneeboard is shoulder width and would easily be accommodated on a 20"-21"wide board.Wider boards offer more volume and more planing area, and increase the outline curve (in such a short length) making turning from a relatively static position a little easier. But the width also make it slower rail-to-rail. My prone boards are 21.5" and even my longboards are only 22.75". What am I missing?

[Smush]

better planing; rail to rail not affected with fin forward design

[NomasTomas]

Moving the fin array up places the fins closer to the spot where the knee rider can place maximum pressure with ankle/shin, but it also widens the distance between the rail fins. This means it takes slightly longer to rotate from one rail fin to the other, as the distance from centerline to rail fin position is now greater. This increased distance is magnified when the board has a full outline, such as found with a 23"+ wide shape. I agree that the fuller outline yields greater planing area, but at the cost of slower turn-response time. Certainly, a full outline is beneficial in small/mushy waves, but even the stand-up rider's mush-busting mini-Simmons typically has a sub-23" width. And yet, 23"-23.5" is the consensus KB width. I'm just curious as to why this is the case.

[Smush]

I guess I dunno

[rippe75]

Lower center of gravity +
Knee to knee , not toes to heel.
= more powerful drivier turns .

Maybe thats what they’re aiming for

Im no design guru no have I ever shaped a board

[southpeakbrad]

Rather than "so wide," maybe it's "wide in comparison to surfboards."
Anyway, kneeboards in the 22-23" width range seem to me to allow a combination of balance while riding, and control, especially if knees are placed closer to the rails vs close together..