A foldable wheelchair (21) and foldable wheelchair frame assembly (26, 126) including a pair of side frames (24, 124, 224, 324), a cross-bracing frame assembly (36, 136) coupling the side frames (24, 124, 224, 324) together for movement transversely between a spaced apart deployed position and a proximate folded position. A variable length link assembly (61, 161, 261, 361) is mounted into and forms a part of the cross-bracing frame assembly (36, 136) in a position between at least one of the side frames (24, 124, 224, 324) and a remainder of the cross-bracing frame assembly. The extensible link assembly (61, 161, 261, 361) being formed for variation of the overall length in a direction extending transversely between the side frames (24, 124, 224, 324) during movement of the side frames (24, 124, 224, 324) between the deployed and the folded positions so as not to force the side frames (24, 124, 224, 324) into unparallel motion which causes the upholstery to bind the folding mechanism. The extensible link assembly (61, 161, 261, 361) is preferably and over-center linkage that is resiliently biased to the extended position. A method of providing a foldable wheelchair frame assembly (26, 126) is also disclosed.