Flater, less curved boards tend to ride faster. just hop on an older continuous board and you will see. because wakes have gotten bigger, no one makes boards with tiny rockers otherwise they'd nose dive.
The flat spot is not a problem in of itself making the board go slower, or rather it is not the only thing. the flat spot gives the board two transitions at each end of the flat spot- two curves and a flat spot (thus "threestage)
It is more difficult for water to smoothly traffic and glide over/through these transitions
also the board is not riding directly on the belly's center but slightly toward the back end. the water hits that flat spot more like a wall (exaggeratedly speaking).
see crude pick bellow
**too much of a transition for the flow to smoothly go around in comparison
The angle alone will slow a board. a 3 stage and a continuous with the same rocker (in inches) will have very different angles. the threestage will have a greater angle and so, again, the water has to traffic this angle more steeply. Even a super bent continuous will actually be slow, like the older Murray. Angle has a ton to do with the speed. Think of yourself hiking up a hill or mountain with a greater angle than the other, it takes longer even if the distance footed is the same?? right
all this also helps explain the "abrupt" or "agressive" or "less predictable pop" of threestage. Now imagine another image. imagine siting in a rocking chair with a little flat spot in it. as you rock onto that flat spot the whole chair is gona buck. thus giving that renowned "bucking style of pop"
Water and the wake is ever changing and unpredictable ("can you ever stand in the same stream twice") and then to throw in another less predictable factor such as a flat spot gives the board its renowned less predictability.
(Message edited by wakerider111 on May 07, 2009)