Pedal Science Blog: How Wide Should Your Tri Bars Be?

Welcome to Pedal Science, the weekly bike fitting blog by Nick Thomas of The Endurance Coach. This week we look at the subject of TRI BAR WIDTH and cycling performance. 

The previous blog discussed how to establish handlebar width and the consequences of riding with incorrectly sized bars. Similar consideration should be given when fitting tribars as any aerodynamic advantage can easily be negated by an inefficient riding position.

Tribars are fitted to increase speed but this can only be achieved if both the following points are realised:

  • The rider reduces frontal drag and achieves a more aerodynamic riding position
  • Power is equal – or higher – than riding without the tribars

When establishing tribar width there are three main consequences when fitted too narrow:

  • Breathing can be restricted if the chest isn’t able to fully expand – this will be more apparent during shorter, faster events where there is greater oxygen consumption and the chest expands more
  • Shoulders become rounded which can lead to excessive tension across the upper back and shoulders
  • Handling can become more twitchy especially if the rider is inexperienced and/or if the bike is set up with a forward saddle position – this can cause the rider to slow down which defeats the object of achieving a fast riding position

Although less common it’s also possible for tribars to be too wide. This can be more comfortable and stable but aerodynamics are compromised - if the tribars are achieving a less aerodynamic position the wisdom of fitting them in the first place needs to be questioned.

Tribar width is relatively easy to establish with most people. When viewed from the frontthe elbows should be positioned slightly inside the shoulders with the hands slightly inside the elbows. A simple test to assess the correct width is as follows:

  • Stand with your arms pointing directly in front of you horizontally
  • Bend the elbows to 90 degree so the forearms are positioned vertically
  • Slowly bring the forearms together across your chest in front of you (keeping them vertical)
  • Stop when you feel tension across the shoulders developing
  • The position of your forearms at this point is about as wide as the tribars should be

When buying tribars ensure they provide a good range of adjustability in terms of bar reach and arm pad width. Tribars which prevent you from achieving your ideal position are not fit for purpose.


It’s possible to achieve an aerodynamic position without compromising comfort, breathing or stability. By performing a simple test you can achieve a riding position which optimizes aerodynamics and enables you to ride to your physical potential.

Nick Thomas is the resident bike fitter at The Endurance Coach. He is a fully qualified bike fitter and expert in lower limb mechanics, holding a BSc (Hons) in podiatry. You can contact him using the email address: or see more about his fitting services by GOING HERE.