When it comes to cycling performance, stiffer means better. Or at least that’s what the bike industry marketeers would have us believe. They may have a point, although just what the word ‘stiffness’ means in bicycle engineering is somewhat more complex than a simple ‘more is better’.
Along with weight and aerodynamics, stiffness is one of the engines that drives modern composite bike design. But while a number on the scales and the way a frame cuts through the air are relatively easy concepts to wrap one’s head around, stiffness is much more difficult to quantify.
Can it be put into numbers? Sure. There are all sorts of complex jigs that manufacturers use to measure stiffness, but for the average cyclist it’s less about exact figures and more about feel. Broken down to its absolute fundamentals, stiffness is the opposite of compliance, which is a mark of how prone a frame is to bending in certain planes.
‘Compliance is a deflection from a defined input,’ explains Reggie Lund, mechanical engineer at Trek. ‘In other words, how much the frame bends when a force is applied
