Equinox Child Carriers produced before 1990 employed a twist lock and eyelet system to secure the sides to the trailer base frame. This system used a fabric flap with hook and loop material to cover an area at the side of the child seat that was vulnerable to a passenger contacting the wheel. This fabric was coupled with a cord or wire tie which held a corner of the blue fabric to the trailer frame through an 1/8" eyelet in the blue fabric. Also, a 1/4" fiberglass rod ran from the top of the side frame to the main frame as a side stiffener.
Often these older trailers are resold by the original owners or two or three owners down the line without all of these components in place.
This will leave an area that a child could put his/her hand through and contact the wheel resulting in injury. Please be sure to protect your passengers.
Equinox offers a fabric replacement package that will fit onto any standard production Equinox trailer. See this link : http://equinoxtrailers.com/store/item/279 One may also purchase the bottom and sides only or convert to other uses and applications of the Equinox human powered trailer system.