I’ve finally got around to installing a running board on the Yuba Mundo. Yuba sells their own plastic versions of these for each side of the bike, but they rely on the treaded bosses which are only present on the V3 frame. My running board was made with plywood using only a jigsaw, and attached to the bike using cheap hose clamps. Getting the shape right was as simple as holding the plywood board in place and drawing the outline of the rail onto it with a pencil. So far I have only added one running board so that I can still tow a 26 inch/700C etc wheeled bike easily if needed.
The board stops the Brompton from falling through the gap in the side-rail, meaning it can be carried lower down on the side rather than bungeed to the top. This lowers the load and means the Yuba handles brilliantly whilst carrying the folder.
It is almost as if they were made for each other.