Thanks to Gas Man...

[derf]

Originally Posted by Particle Man

Hmmm - wonder how they did that?

Steel supports that were bolted to the seat pan, extending off the sides and down just past the bike, then he had pads that sat on the rear footpegs to take the weight of the seat pan and keep the assembly from shifting or rocking side to side. The whole thing (quite heavy when full) just un-clips off the tail with the turn of a key and pulls right off.