With all the trouble I'm having navigating the FIM rules -- I find it hard to believe that I'm offering something from them, but here's a cut-and-paste from those pages: (Whoops. It's in .pdf form and I can't copy and paste, so I'll just type a bit...):
"Group B2: Motorcycle with permanent sidecar: Vehicles with three wheels, making two or three tracks on the ground in the direction of forward travel, with a permanently attached sidecar forming a complete integral unit.
Group B3: Cycle-cars: 3-wheeled vehicles making three tracks on the ground forming a complete integral unit and having accommodation for a rider and a passenger.
A cycle-car is a motorcycle with 3 wheels differing from a Sidecar in that 2 of the wheels are mounted on the same geometric horizontal axis. These may be on the front or rear of the vehicle and shall ensure stability of the vehicle.
Steering must be by handlebars with a minimum length of 500 mm or by a wheel with a minimum diameter of 300 mm.
The passenger can be by the side of the rider but not necessarily in the same frontal alignment. He can also be placed behind the rider. If bodywork does not enclose the wheels, wheels must be protected by mudguards."
That's all from the FIM "Appendices for World Records". I've got the whole thing and could forward it if you'd like it. You can get it from FIM, of course, and I think it's also available on the Bub's site.
Remember, I'm not the FIM representative by any stretch of the imagination. I just happened to have seen this information and knew where to find it.
