Reynolds 731 OS professional tubing

731OS – Oversize tubeset introduced in 1992.

Features double butted oversized main frame tubes, with laterally aligned stiffening ribs on the butt sections to maximise stiffness and tortional rigidity, as with the 708 Classic set. 731OS race is approximately 10% lighter than comparable competitive tube sets and is suitable for road, track and timetrial frames at professional level’.