Abstract: A device for measuring five parameters which define the riding position of a bicycle, which device may also e used as a jig to guide adjustment. The five parameters measured are: position height, saddle setback, saddle angle, reach to the bars, and bar angle The device treats these parameters as functions of a given rider's anatomy, and compensating adjustments factor out changes in crank length, height of shoe sole or height of pedal which would otherwise alter a rider's “reach” to the pedals. The device includes the scales and gauges needed to perform all measurements or to be used as a jig, as well as the fittings needed to attach it to a bicycle. No other tools are needed, and no disassembly of the bicycle, including crank bolts or cranks, is needed.