what you could do is make 'em 50/50 all the way through and try it out.then, if you feel like it, you could bondo the last 16" of rail and put an edge on 'em.ride it and compare. if you like the hard edge, great! if not sand, off bondo back to original rail…i’ve done this on several boards.
Dats a moderate width eggshape, and can be used for small or bigger (up to 8’) waves.
So, do you surf in glassy conditions most of the time? If so, go with really hard resin built up edges for quick snappy, responsive feeling.
If you like a duller feeling because you do big hard turns, then go softer with the hard edge maybe only 8" up from the tail.
If you surf mostly bigger, bumpier conditions, are learning still somewhat, then the above rail can be good for a safe, easy, not too quick responding board.
And if you boatin to secret spots 10 miles N, then a harder, longer hard edge would give you more and quicker response as you mid and nose ride your way out of hollow tubes.
If the wave has power and speed, you can ride softer tail edges that hold in and give you control.
If the wave is slow moving, whether fast peeling or not, you need harder edges to get up and going, to give you the feel of quickness, sharpness, and response, so harder edges longer from the tail is the call.
I’ve found that a tucked under rail is the best. It’s always easier to make a fast board work in slower waves than it is to make a slow board go faster.
I have several egg shape single fin boards from 6’6" up to 8’. I have boards with 50/50 rails and others with extreme down rails, and the 60/40 with a tucked under rail seems to work the best in all conditions.
That edge on the bottom lets water flow away cleanly and really makes a difference in good waves. No edge and you find the board just won’t get into overdrive when you need it to.
I also don’t like the rail square at the bottom edge even at the very end.
Here are some pic’s of my 6’10’’ egg. When i got i thought it was a little narrow, but i dig it!!. Paddles great, catches waves great, and i can ride this board with my front foot a few inches from the nose pretty easy ( on non hollow waves ). Its 15x21 3/8x15x2 3/4. Im 85kg and 5’9. Mine has a hardish edge through the last 16’'. Not razor sharp, but not round and dull either. I love mine, and now its 50/50 between my twin keel and this.
I went for an 60/40 rail with a hardish down edge at the tail (not short board sharp…)
the rocker ended up being 4 1/4. I wanted it to be low for a kind of mini-longboard feeling compared to a more hybrid/funboard rocker. I understand that the original eggs from the seventies where pretty flat with not much rocker at all…