Bicycle safety and conversion wheel

Claim 1

In combination with a conventional bicycle having a frame, a rotatably mounted front wheel, a rear axle secured to said frame, a rear wheel rotatably mounted on said rear axle, a seat post, a seat mounted in said seat post, and a seat support structure having two distal ends, one of said distal ends connected to said seat and the other of said distal ends connected to said frame adjacent said rear axle, said bicycle having a stable mode of operation with both conventional wheels in ground contact and a semi-stable "wheelie" mode of operation; the improvement comprising: elongated bar structure fixedly secured to said frame adjacent said rear axle and arm structure relatively shorter than said bar structure fixedly secured to said seat adjacent said seat support structure, said arm structure and said bar structure being fixedly secured together higher than said rear axle when in said stable mode of operation, a mounting plate carried by said arm structure and bar structure adjacent their securement, an auxiliary seat mounted on said arm structure between said seat and said mounting plate to accommodate a passenger thereon, and a wheel assembly mounted on said mounting plate, said wheel assembly having a safety wheel thereon so that said bicycle can be operated in said semi-stable mode of operation with said safety wheel and said rear wheel in ground engagement.