I felt the friction of the bungee sliding over the fairly pointed edge of the rudder mount was contributing to the difficulty of the bungee keeping the rudder in its down position while sailing. I felt the combination of the buoyancy of the hollow rudder, the water pressure while under sail, and the friction at that one point was overpowering the effective elasticity of the hold-down bungee as applied to the rudder. I decided to try putting in a roller for the bungee to go over to remove the friction at that one point.
I simply used a 3/16″x1″ Clevis Pin, a 3/8″ Cotter Ring, and a 1 ” Nylon Spacer (.257 inner dia, 1/2 outer dia) which I had to cut with a hacksaw to get the length just right.
The nylon spacer will rotate around the clevis pin. Metal parts all stainless steel of course.
I drilled two small holes in the rudder mount just big enough for the clevis pin and installed the parts as shown below.
The pull-down bungee and rudder lift line now go as follows:
With the bungee applying enough tension to hold the rudder down while under sail, the nylon spacer would rotate with the bungee whenever the pull-up line raised the rudder. When the pull-up line was released, the nylon spacer would again rotate with the bungee as the rudder went back to its down position. This seemed to work quite well while under sail and the rudder remained in its proper position.
[EDIT: I’ve found that I need to oil the roller before I go out each time to make sure it rotates freely. I now keep a can of WD40 in my boat.]