Figure 22 comprises nine photographs showing how the bicycle is folded. Photograph (a) shows the bicycle in normal configuration. The bicycle has small wheels and a single near horizontal beam joining the front and rear of the halves of the bicycle. The seat and handlebars are each supported on tall struts. There is a rectangular luggage carrier over the rear wheel which has castors fitted to each of its four corners. So far, it looks very much like the Dahon, Trusty and Bickerton bicycles except that there is no large hinge visible in the beam just in front of the chain wheel. Photographs (b), (c) and (d) show the first fold and this is quite different from the previous designs. The frame supporting the rear wheel is unlocked from the beam and the whole rear wheel assembly rotates round the centre of the chain-wheel. The rear wheel ends upside down underneath the central beam. This beam has been bent to accommodate the rear wheel in the folded position. The bicycle is now sitting on the floor on the castors that were on the top of the rear wheel luggage carrier. Photographs (e) and (d) show the second fold in which the front wheel assembly is unlocked from the beam and allowed to rotate vertically through 180 degrees so that the front wheel ends up next to the rear wheel with the chain wheel sandwiched in between them. It is now clear that there is a hinge in the beam just behind the front wheel assembly. Photographs (g) and (h) show how the front handle bars hinge down and rotate so that they too can be placed between the two cycle wheels. Finally photograph (i) shows that the seat strut has been collapsed and the seat ends up sitting directly on the top of the folded assembly. In the final folded state one of the pedals is tucked in next to a cycle wheel but the other pedal is still sticking out from the assembly.

 2.3 Prototyping and improving