A synchronous belt drive system comprising a first obround sprocket having a toothed surface and at least one linear portion disposed between two arcuate portions, the arcuate portions having a constant radius, the linear portion having a predetermined length, a sprocket having a toothed surface, the sprocket engaged to the first obround sprocket by an endless toothed member, and the first obround sprocket having a magnitude and a phase such that an angular displacement timing error between the sprocket and the first obround sprocket is less than 1.5 degree peak to peak.