Pedal Science Blog: Bike selection for triathlon

Welcome to Pedal Science, the weekly bike fitting blog by Nick Thomas of The Endurance Coach.

We've not yet reached the end of 2015, but many triathletes are already considering a new bike for 2016! The big question to answer is road bike or time trial bike? Nick gives his view on the subject below:

For anyone competing in triathlon there are several considerations when selecting which type of bike to race on. Riding experience, handling skills, ability and course profiles all influence the choice of bike.

A road bike geometry positions the rider further back than a time trial bike which provides a more stable ride. As the front end is generally higher a more comfortable position is achievable and for most people this provides the most sensible riding position. The geometry also provides superior handling when climbing and descending than a time trial bike so proves to be the logical choice especially if the bike is to be used for hilly races or sportives.

A time trial bike is designed to be raced on flat/undulating courses where there is little variation in speed. Riding position is further forward and the front end tends to be lower than a road bike resulting in a more direct power transfer and improved aerodynamics. However if you’re not averaging more than 20 mph for the duration of the event the aerodynamic gains will be negligible. Poor handling skills and/or low confidence will affect riding speed so the benefits of the race geometry are not realised.

A course which features climbs, descents and cornering would influence the choice of bike. Time trial bikes are less efficient when climbing and relatively unstable when descending and cornering which makes them unsuitable for many people.

The longer the distance the slower the average pace will be so this should also be factored into the choice of bike: racing a sprint distance on a flat course will be considerably faster than Ironman UK or Ironman Wales. Bottom line? If you’re averaging over 20 mph with good riding skills you’d benefit from a time trial bike. If you’re a slower rider and want a bike which provides more versatility a road bike would be more suitable.

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.