I started teaching my friend how to shape and of course he had many questions. When it came to rails, I found myself talking in loose terms. To clarify things, I thought I’d run this by the forum to see if Im understanding it correctly. Wave conditions and power here contextual to NJ.
SOFT 80/20 RAILS IN STRONG WAVES
Example: 80/20 full profile with no hard edge. Works well in stronger waves (150-800kj) because the water wraps around, pulling it into the face, providing hold, where a sharper rail would slide out. Low volume boards will paddle slower with this because rail area now sits deeper in the water, causing drag. However, once up and planing, the wave itself provides the power needed to lift it up higher out of the water, generating speed. Higher volume boards with this rail will be easier to paddle because the rail is floating higher up out of the water, reducing non-flat surface contact with the water. But on a stronger wave this added volume with this rail can feel less responsive. This is because the plane effect lifts even more of the rail up, prevents it from wrapping into the wave face.
SOFT 80/20 RAILS IN WEAK WAVES
On weaker waves (60-150kj) this rail can feel neutral and unresponsive because less wave energy means the board is moving slower. This lack of force makes it harder for the rail to penetrate the wave face. Adding a tuck increases speed because the water sheers out from the bottom, getting it to plane earlier and going faster.
HARD 60/40 RAILS ON WEAK WAVES
Example: 60/40 profile with formed or hard edge. With the proper amount of board thickness throughout, this rail will plane earlier in weaker waves (60-150kj) than a full soft rail would. This is because the radius that contacts the water has less height to get up on top of the water surface. It also turns faster because a sharper angle at the bottom part of the rail penetrates the wave easier than a full taller rail. This makes it more responsive and hold better on the face of a wave. But if you pinch this too much, or place it too far up, or on a rail line that’s too straight, it can hang up, feel like its tracking.
HARD 60/40 RAILS ON STRONG WAVES
On stronger waves (150-800kj) this rail is still faster than soft rails, but can slide off the face. This is because it has less area for the water to wrap around and a rail requires more energy to penetrate faster waves.
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