I found this a while back,most of you already know this or may have even read it,I found it usefull when I didn’t know the performance characteristics of different rail shapes.
Hey Chris, good thread. I have two boards with the full length rail edge. Both are quick to accelerate and fast. Very Fast.
I’ve never experienced the lack of control mentioned by horsemouth. However, I would not try to get back control as he did, by softening the edge, but rather by playing with the fins. Griffin’s five fin design offsets any lack of control by putting a lot of teeth in the water. So you get fast with control. And anyone who thinks the five fin will be stiff will be suprised. I think it’s looseness comes from the reduced fin spread (the rears are up at about 5" as opposed to 3-1/2" for a typical thruster, the fronts are about the same).
I’m not sure, but I believe he puts the edge on all his designs, including his thrusters and twin fins. But he studies his fins very carefully.
One of my boards with the edge has a unique fin setup- small side bites about 12" up and then a slightly larger than normal thruster center fin at about 5" up. I would have never thought this was enough fin but I’ve almost never spun out. Not even with the hard edge. My next board will be a smaller variant of this set up. I will also learn how much of the speed is due to the edge, and how much is due to the reduced tail rocker on these boards. The reduced tail rocker has some negative traits- makes late drops harder and makes it harder to go vert and the board sticks in the lip.
…all of which could be overcome if I had more skill… 
or better waves 
Maurice Cole is another shaper who uses sharp edges up to the nose.
After reading this thread, i sanded a hard edge onto my little eggy board with round rails. From the front foot back to a few inches in front of the fins is definately an edge, but not sharp. Hard to explain, but in the light, you can see the transition from flat to round is visible, though doesnt feel "crisp" to touch. From just in front of the fins, it gets sharp enough to definately feel. Hope to try it out sometime this week, though its looking like my good wave board might get wet. WIll update if i surf it and notice a difference
carefull guys, its addictiv, i changed the 2. board hihaa booom and soon one more. i can´t be stopped any more at least not on my boards…;o) por cojones
saludos
uzzi
…hello,
that reduced tail rocker problem solution is to reduce the board length by 6" (adjusting the planshape too)
…65% of the boards I build, are with and edge…
-in early 90s I made all with edge all the way (not hard as in tail) and with kind of a “bevel”; son not so rounded in that “rail line” area.
very thin foiled rails, overall low volume boards, super rockered and all 6 3 to 6 10
I remember that I didn t tapered out the tails and noses foils as I do now.
so, if you want a hotdog board go with that
if you do a snapback, with this you have ease to perform a slashback
if you do a slashback now you can do a re entry tail slide.
Are very good for projection boards too.
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After reading this thread, i sanded a hard edge onto my little eggy board with round rails. From the front foot back to a few inches in front of the fins is definately an edge, but not sharp. Hard to explain, but in the light, you can see the transition from flat to round is visible, though doesnt feel "crisp" to touch. From just in front of the fins, it gets sharp enough to definately feel. Hope to try it out sometime this week, though its looking like my good wave board might get wet. WIll update if i surf it and notice a difference
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Yeah, i definately think it helps. Tried it today, and it felt like as soon as i popped it, it took off, and didn't seem "stuck". Before, i seemed to have to work to get it "free", but today it was pop n go!!. Could have been me having a good day, but i think the edge did something. Ben's rainbow keels went great too, had a great backhand wave on the egg. Think im sold !
I have added some rovings along 2 edges of my chine railed finless board, they are raised by about 3mm and run from tail tip to 3/4 to the nose...only had one surf so far, needs modifying but might post some pics.....
Hey pridmore,I’ve thought of doing something similar,please post pics.
I'll take some pics but it wasnt a success, I sanded its edges down to about 2/3's of what they were, first surf was catching heavily when spinning, ok for trimming straight but no big improvement , corked my leg badly today while surfing it, the rovings on a blocky hard edged chine rail made for some decent edges and it got me good.....