A Safer Rear Mounted Parking Brake

by Bob Dill - March 1988

Rear mounted parking brakes have a couple significant advantages over front mounting: The boat won't blow backwards off the brake on a windy day and the boat pushes a lot easier if you forget to take off the brake at the start of a race. They have one major disadvantage: They occasionally get rotated up high enough to tangle with the bobstay. This results in a partial or complete loss of steerage. This always is a source of a good scare and can be dangerous in a race or near an obstruction. It usually happens on bumpy ice or when there are snow drifts to push the brake up.

The traditional solution to this problem is to keep the brake pivot bolt fairly tight. This works pretty well most of the time but requires careful adjustment and monitoring. It also makes the break harder to move.

A more reliable solution is to move the brake pivot down about 7/16 of an inch and forward about the same amount. A 1/2" long, 1/8" or 3/16" diameter expansion pin (also called a split pin" or spiral pin) is then put in just above the brake when it is in a horizontal position (See Drawing). This prevents the brake from going above a horizontal position and keeps it away from the bobstay. The position of the expansion pin hole should be established after the new pivot hole is made and the brake remounted. It should also be mounted as far back as reasonable. A slight difference in pin position makes a fairly big difference in the "up" position of the brake. Sarns plate runners are only hard within about 1/2" of the sharp edge. away from the sharp edge" they drill easily with a sharp drill.

The only drawback to moving the parking brake down is that it will drag a little more in deep snow. In a four inch drift the increase in drag is trivial because your plank will also be trying to plow through such a deep drift.

While you have the runner in the vice, put the brake in its down (forward) position and drill a 1/4" hole just behind it an inch or so from the bottom edge. put a countersink on each end of this" hole. When you have to leave your boat parked for a while you can put a pin in this hole to prevent the boat from sailing off the brake. Fast pins work well but a bolt (without a nut) or anything else that will sit in the hole will work fine. I use a fast pin (a 1/4" by 1" pin with a spring loaded ball in the end) attached to a short piece of Velcro. I have a little Velcro glued to the front bulkhead. That way the pin is convenient and easy to find.

Note December 1990:

Expansion pins can be found in most hardware stores. I have used unplated ones with good success. However, if you would like a stainless pin I have about 100 of them (3/16" by 1/2"). Send a dime taped to a piece of corrugated cardboard with a stamped, return addressed envelope to: Bob Dill, 21 Marian St, Burlington VT 05401.

They also work for sailboard fins. They are a little shorter than the standard 9/16" (5/8"?) length and they work well.

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