sergei Scotland wrote: ↑Sun Dec 02, 2018 1:00 pm
Beginner's question obviously - but really-why?
Being wide a 135x50 or 135x 48 would probably work well in lighter winds and for beginners. After all it has 20% bigger surface area compared to 135x40.
It would presumably work well in higher winds too as most people say that shorter boards are better in stronger winds as they curve better and sit deeper in the water with less of a tendency to skim sideways.
Instead one has to go to 148 to get 48 cm wide board and most /some people say this is too long for powered conditions.
Scaling, and your desired dimensions are at the edge of the optimum.
TT length is related most directly related to height of the rider. As the rider height gets taller, the board gets longer to allow for more distance between their foot positions. Since "pearling" or "sinking the nose" becomes a problem as the feet are moved closer to the tips of the board, more board is added at the tips. Thus a taller person typically needs a longer board.
TT width is related to foot length (toes to heel) as this is the lever arm by which force is applied to the board. As foot width goes up, more force can be applied to the heel AND toe edge. Or that can be looked at from the other way - the wider the board, the more force the heel (or toe) edge generates. Thus a longer foot is needed to hold down a wider board.
When you scale a persons weight up, typically you get more weight as you grow in height and foot width. As you scale down in weight, you loose height and foot width. That is not to say that there are not tall lightweights out there, nor that that there are no short heavy riders. But those are the extremes and that market is niche that may not warrant production of a size range this far out of the norm.
If you are 5'-4" tall, with size 12US feet, and weight 220lbs, you may need to look into custom boards. And that would likely get you to the board size you mentioned.
There are other ways to get to this board size too. One way would be to move the foot pad placement closer to the heel side edge. But this sacrifices toe side edge capabilities. Another way to get to this board size is to always be underpowered enough to where the extreme width at the edge does not overpower a smaller lever arm (foot). But if the wind suddenly picks up and a smaller footed rider is on too wide of a board, edge control is lost and the board cannot be safely managed (or just becomes no fun).