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What should be measured in a good triathlon bike fitting?

Joe Beer explains the three stages that should take place in a good triathlon bike fitting service

Nikki Bartlett riding Cervelo triathlon bike
Credit: Eric Alonso / Getty Images for Ironman

When you have a triathlon bike fit, it’s important that several measurements are taken. They may be simple, but they have a big influence on comfort, aerodynamic efficiency and power output.

Before making any changes to your triathlon bike, all good bike fitters will record your current set-up. They’ll note down your seat height, saddle to bar drop and the distance between the aerobars and the floor.

And then your bike fitter should take at least three more triathlon bike fit measurements: your knee angle when pedalling, your knee-to-elbow gap and your saddle tilt. Below we’ll explain why these matter.

Knee angle

One foot is placed horizontal while the pedal is at the bottom dead centre and the upper body is in the aero position.

Your leg can’t be dead straight behind the knee and your hips mustn’t roll over and downwards, so as to allow the foot to maintain flat.

Aim: A solid riding style that allows the foot to push down without excessive toe pointing.

Knee to elbow positioning

The next measurement that matters during a triathlon bike fit is the gap between your knee and elbow.

When pedalling in the aero position your knee should come within 4-7cm of the back of the elbow.

Though some riders reach much further forward this can adversely affect handling, engage too much core muscle and prevent a low, safe head position.

Aim: The upper arm to be between vertical and 10-20° off vertical. This keeps the elbow close enough to the shoulder to aid handling and comfort.

Check for neck strain

On the aerobars you should be able to look ahead without straining your neck.

Ensure your saddle is at or very close to horizontal – you don’t want to fall onto the handlebars.

Also check the forearm cups aren’t too low.

Aim: Your torso silhouette to be slightly upward from the hip to upper chest area. This gives space for the knees to pedal without hitting the stomach and also helps digestion and breathing.

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The 220 Triathlon team is made up of vastly experienced athletes, sports journalists, kit reviewers and coaches. In short, what we don't know about multisport frankly isn't worth knowing! Saying that, we love expanding our sporting knowledge and increasing our expertise in this phenomenal sport.