Anatomy of a Kickup Rudder
By Dale Mack
November 6, 2001

At 38 lbs., the kickup rudder's convenience comes at a price in added weight and increased maintenance.  I've periodically disassembled my rudder on my 1987 C22 (#14286) to check for potential problems and to examine its inner workings.  Here's my hypothesis as to why some boat owners find the system won't keep the rudder blade down after a number of years.

When I removed the machine screws and lifted the side pressure plate, I noticed that the top housing is hollow.  I also noticed some early signs of corrosion.   I've sailed the boat in salt water several times, and have always washed it down afterward, but there was corrosion nonetheless where the stainless steel screws attached, as well as some surface pitting on the aluminum plates.  None of the problems were serious, but it did underscore the importance of paying attention to the maintenance needs of the kick-up rudder.

The Lanyard

In the raised position, the blade is held up by a combination of the pressure plates and a lanyard.  The lanyard passes through a hole in the aft portion of the blade and up to a sheave at the top of the rudder.  From the sheave, the lanyard is redirected to a tube-style vee-cleat.  The system has worked fairly well, although I've heard reports of the cleat failing and needing to be replaced.

Keeping the Blade Down

Several owners have reported difficulty with keeping the blade down when the winds are moderate or above. The response is usually to tighten the handle in an effort to generate greater friction.  There has been at least one reported case of the blade cracking and breaking off while sailing, apparently due to over tightening.  It appears that over tightening resulted in stress cracks that allowed moisture to seep in and weaken the rudder.

By design, the system relies on a rivet popping into a hole in one of the pressure plates when the blade is pushed down into position.  The combination of the rivet's location and the pressure plates are designed to provide just enough friction to keep the rudder down, but not so much that it cannot easily kick up in the event of grounding.

Why the Blade Won't Stay Down

Assuming a rudder isn't missing the rivet, I suspect that the problem is related to a groove that forms on the inside of the pressure plate facing the rivet.  I've watched the depth of this groove increase over the years on my boat.  Although some of the damage is related to past groundings, most of the wear seems to be the result of not loosening the pressure plates enough before pushing the blade down or pulling it up.

Although several owners have resorted to installing shear pins as a method of holding the blade down, I'm inclined to pursue a solution that restores the lip of the hole.