Lessons from the wind tunnel

The term ‘aero’ must surely rank as one of the most used terminologies amongst triathletes. The discussions surrounding the ‘aeroness’ of a certain bike, wheel, helmet, gel or any other piece of bike equipment for that matter, can often result in a heated debate. I must admit that I can be slightly obsessive about aerodynamics too because, after all, #AeroIsEverything isn’t it?

A few months ago I was given the opportunity to visit the Specialized ‘WIN’ tunnel in California to do some testing with the experts in aerodynamics. For readers who are expecting the rest of this article to feature overly complicated, specific numbers that will make you feel like you are in a university physics lecture, rest assured that this is not the case. The process of aerodynamic testing in the wind tunnel was enlightening in the sense that it opened my eyes to what triathletes should be focussing their attention on. Sure having a Ferrari of a bike which is set up in the most aggressive position possible might get you a few more likes on your next Instagram post but the reality on race day might tell a different tale.

The most overlooked component of aerodynamics comes down to your bike fit. A lower and more aggressive bike fit may save you a few seconds or even minutes depending on your race distance. However, if you are uncomfortable and unable to stay on your aero-bars, then any aerodynamic savings immediately become irrelevant. The flow on effect of an aggressive and uncomfortable position may also mean that you are unable to run well off the bike due to the increased stress on your body. Many people watch cyclists on their time trial bikes and believe that as triathletes, we need to copy this blueprint. However, pro cyclists do not need to be able to run off the bike, and their race TT distances are generally shorter than what we race in triathlon for half or full iron distances especially.

The goal is to be able to spend the vast majority of your time in the aero position and feel comfortable while doing so. Comfort should always be your priority followed by aerodynamics. Once you have a bike fit which allows you to stay aero without placing a strain on the rest of your body, the second part of the equation is to practice! To help achieve this, it is imperative that you spend time training on your bike in the aero position.


This concept of comfort before aerodynamics should also translate to your choice of wheels. Most triathletes want a deep section front wheel and rear disc wheel without really thinking about the true underlining advantages and disadvantages. If you are a lighter athlete and decide to ride the aforementioned wheel combination, then this may result in feeling unstable in the event of just a small amount of cross wind. This feeling of instability may lead to tenseness in your upper body and may mean that you won’t even be able to stay on your aero-bars in fear of being blown off! The general rule is that in most situations, you want to choose a wheel combination that allows you to feel confident and relaxed while you are in the aero position no matter what the wind conditions throw at you.

For lighter athletes, this may mean that you will ride a lot quicker with a shallower wheel such as a Roval CLX40 versus a deeper wheel or even a rear disc.

Without question one of the biggest mistakes that I have seen triathletes make when it comes to aerodynamics is how they decide to attach hydration, nutrition and mechanical spares to their bikes.The time savings that come with smart choices in this department can be truly staggering. Some of the biggest culprits are water bottles on your bikes down tube and energy gels strapped to the top tube. It may not seem like a big deal to most athletes, but all of these factors have been proven time and time again in the wind tunnel to cause significant aerodynamic drag. Moving your water bottle to behind your saddle or in between your aero bars, which are both areas of ‘negative drag’, results in absolutely no additional aerodynamic drag. Your nutritional items should also be strategically placed so that they are hidden away from the wind to avoid any aerodynamic losses. Many athletes commonly tape gels to their bike frames rather than hiding them away in integrated bike storage solutions such as the storage solution Specialized has with the Fuel Cell.
When it comes to aerodynamics,I believe that too many people are missing the big picture. The more comfortable we are and the longer we can stay ‘aero’ for, the faster we will be on race day.


Sam Betten

Leave a Reply

Your email address will not be published. Required fields are marked *

Sign up for the mailing list

Enter your details below to stay up to date with whats going on.