Setting your saddle height

The saddle is the only part of the bike that connects you to the frame through your own weight. The handlebars, by contrast, carry almost nothing: they steer, they do not support. That is why most of the discomfort people blame on the handlebars — tired wrists, a hunched back, tense shoulders — disappears when the saddle height is right and the bars are simply lowered to saddle level.

A saddle that is too low forces the knee to bend further at the top of the pedal stroke, which lengthens the moment of loading and asks more of the front of the leg. A saddle that is too high stops the pedal from dropping far enough: the leg stays half-bent at the bottom of the stroke, the hip starts rocking, and the ache moves up to the lower back. In both cases the pain does not arrive immediately. It arrives later, at a distance, once the mechanics have had time to settle in.

The starting measurement is the distance from your ankle bone to the floor, standing, feet flat. It gives a base, not a final figure: two people of the same height can have different inseams, and the inseam is what counts. A setting derived from it puts the pedal in the right place for most riders, but it then needs adjusting.

The adjustment is done by feel, on two criteria that involve no numbers at all. First, at the bottom of the pedal stroke — foot on the front of the pedal, heel resting on the platform — the leg should stay very slightly bent, not locked. Second, stand up on the pedals with your feet flat: the knee should track roughly vertical, tilted slightly forward. If you have to climb onto the pedal to reach it, the saddle is too high.

Four sensations are typical, and each points one way. A knee that complains at the top of the pedal stroke, right as the foot passes its highest point, comes from a saddle that is too low. A lower back that pulls after a few kilometres comes from a saddle that is too high. Numb hands, or pressure between the sit bones, are not about height at all but about the wrong bike: a saddle too narrow for your pelvis, which no height adjustment will fix.

The fourth sign is the quietest, because endurance buries it: your weight rocking from one side of the saddle to the other on every revolution. If you notice that movement without thinking about it, the saddle is too high or too wide. In both cases the body compensates by rocking, and it is that movement, more than the height itself, that eventually shows up in the lower back.