There are several well-known companies that produce steel tubes for bicycle frames – these include Reynolds, Columbus, Tange, Tru-Temper and Dedacciai. Each produces a range of different grades of steel tubing, as well as specific tubes for particular applications. These can be lighter or heavier, more or less resistant to bending/flexing or more or less able to withstand rusting.
Part of the art of creating the “right” frame for an individual is the ability to match the tubeset to best suit that person’s individual needs. Because Chas will produce a custom specification for every client, we don’t usually specify a tubeset for the various Roberts models – it changes for every frame that we make.
The simplest tubes are straight gauge – the wall thickness of the tube is constant from one end to the other. However, because of the mechanical properties of tubes used in bicycle frames, the wall thickness only needs to be relatively substantial at the ends, where the brazing or welding will occur.
This led to the development of butted tubes (thicker tube walls at one end) and double-and even triple-butted tubes (thinner in the middle, thicker at both ends). These save weight and affect the “feel” of the finished frame.
There are many other ways in which the steel tubes can be manipulated to affect their characteristics – rifling, denting, cold-working – and some tubesets are asymmetric, to reflect the different forces that come to bear on the drive side (the right side when looking down – the chain side) and non-drive side of the bicycle.
The right balance of tube gauges, profiles and diameters is also important so the bike best fulfils its owner's needs. We have some tubes that are designed specially for us so that our smaller bikes perform as well as the larger ones. Touring bikes should be stable and not "whippy" under load, racing bikes should be as light and responsive as possible. Our Audax bikes combine these tubing characteristics to provide a blend of stiffness, suppleness, exceptional road “feel” and damping, resulting in what we believe is the most comfortable bike ride you can get.
Roberts Cycles, 89 Gloucester Road, Croydon, Surrey CR0 2DN, England
Tel: +44 (0)20 8684 3370
PRIMER - Tubes