I spent a good bit of time thinking about the hitch. My favorite part is using a short piece of automotive heater hose to wrap around the bike seat post. It flexes a little, absorbs small shocks, and attaches and removes quickly with no tools. I like it.
The trailer has a wooden frame with low-speed low-pressure wheels, slightly smaller than wheelbarrow wheels. They roll nicely and absorb minor shocks.
It's all connected by a long piece of black iron pipe, bent to the contours of the rear bike wheel and the bow of the kayak. And the pipe swivels in the frame so everything moves.
I designed this hitch to fit around the bike seat post.
Movement: - Yaw: The rubber hose allows the hitch to swivel about the seat post as the bike turns left and right. - Roll: The big bolt and nylock nut allows the hitch to swivel as the bike leans side to side. - Pitch: The rubber hose and rubber bumper allows a little movement as the bike and trailer move up and down.
Installation and removal: - Two metal pins hold the rubber hose to the hitch. - To remove the hitch from the bike, simply remove one pin from the hose, then slide the hose off. - To install the hitch, slide the hose over hitch, then install pin.