The diamond shape of a bicycle frame hasn’t changed much since it was first invented. Triangles are an enormously strong shape and can also be easily modified to accommodate riders of different statures. Each rider’s needs may vary, but the essence of the design need not change drastically.
A well-built bicycle transfers power efficiently through the drivetrain, steers predictably and is comfortable to ride for long periods of time. Overemphasizing stiffness creates a bike that turns every variation in the road surface into numbing vibrations while focusing too much on compliance makes a bike that handles unpredictably and loses energy through undue frame flex. It is in the harmonious middle ground between these two extremes that good bicycles exist.
