A Roy Stewart surfboard design secret: Fore and aft mass distribution in longboard design.

 It's often assumed that if possible the mass of a surfboard should be placed as close to the middle of the board as possible. The reason for this is to reduce 'swing weight' by reducing the inertia required to swing the nose of the board through turns. It's also a concept taken from boat design where weight in the ends is avoided as much as possible in order to reduce pounding and pitching.

 Fore and aft weight distribution/concentration with surfboards  is however just another design element, and I don't agree that it is always better to have it concentrated in the middle of the board as much as possible.

Unlike the situation with boats ( unless they are surfing ) the majority of the force which moves the surfboard is not only proportional to mass it's also positioned and distributed as the mass is distributed. Because of this mass can be distributed towards the ends of the surfboard in order to achieve a desired result, as by moving mass we are moving the centre of effort and the distribution of effort.

So for example I use nose weight as a design element as it is used to provide motive power from the nose. This works as a means of assisting penetration and control on takeoff, and for control of glide path angle in general.  Thus for example in order to drop down the wave in a steep high line situation when trimming  one can use the motive power of the nose mass. If part of the inside rail is released the nose mass will exert greater leverage and will increase the glide path angle by lowering the  nose. This is very useful as it adds a whole new control method which surfboards  with lightweight noses are unable to use,  one which has great advantages over the usual methods of trimming forward or tail turning, as well as  adding to those control methods.

Turning and trim control using the method described is very organic and intuitive, it is also able to be used with great subtlety.

I've never seen this written about or spoken of before, nor have I seen it used in longboard design or properly in the water except with my own boards.

In order for the concept to be utilised effectively rather than incoherently in an ad hoc or accidental way, the board needs to have certain other design elements, fortunately these are also features which are required for other aspects of functional pure surfing boards, in a perfect example of the harmony which exists in design when one eliminates the spurious and unnecessary.

So this is an answer to those masses of uneducated people ( like Randy Rarick for example ) who say that if there's a lot of nose out of the water when one of my boards is at speed that it shows that the nose could be removed.   The answer is that the nose is doing vital work when out of the water ( provided that it has suitable mass )  I haven't mentioned the details  previously because although I like to share design knowledge  I also need to keep some to myself away from the prying eyes of the corporate vultures !