Aerobars, which are also known as triathlon bars, are handlebar extensions with padded forearm rests that allow the rider to get into a more aerodynamic position by drawing their body forward into a tucked position, with a dropped torso.
‘Clip on’ styles can be added quickly and easily as they bolt onto both normal handlebars and aero base bars (aka cowhorns). Clip-on tri bars cost around £50 with prices rising depending on materials and weight. Complete ‘combi’ bars (base bars with integrated aerobar extensions) are more expensive and theoretically more aero.
An optimal aero handlebar set-up favours the minimum frontal area with your forearms extended out in front of you. The closer together you can comfortably get your elbows, the better, as they’ll act like a fairing and direct the airflow around the rest of your body. Your back should then be as flat as you can make it with your knees just skimming your chest when they pass through the top of the pedal stroke.
After Bradley Wiggins’ successful Hour Record attempt, the component of his bike that attracted the most attention was his 3D printed titanium aerobars. Designed and machined precisely to his position, they played a major role in his staggering 54.526km ride. With a rider’s frontal area one of the key determinants for drag, bars that facilitate a low and narrow position have been sought since the importance of aerodynamics was first realised.
However aerobars aren’t a one-shot, go-faster solution for triathletes. For the rider, aerobars can facilitate a more aerodynamic riding position but, if that position isn’t sustainable or compromises power output too much, the net result can be less speed. The bike, its components and the rider have to be considered as a whole dynamic unit.
Focus too much on one part, such as the bars, and the real-world riding results may surprise and disappoint you. Andy Smallwood, Boardman Bikes company director, found this to be true when developing their TTE bike.
“When we took Pete Jacobs’ Kona-winning AiR 9.8 set-up and started using it as the baseline for our new TTE model, we decided, within the parameters of fit and adjustability, to make the cockpit as aero as possible,” says Smallwood.
“CAD and CFD testing on their own showed the new bars to be extremely slippery, and the bike, as a whole, was posting numbers showing it to be 14-24% faster. But when we factored in a rider, the whole set-up was 4% slower. The problem was the bars were too good. The air was flowing over them but then slamming into the rider’s knees. Learning from this, we redesigned the bars to manipulate the airflow and produced a whole set-up that was 4% faster
Adjustability is a vital factor when it comes to aerobars, as the wrong set-up can impact greatly on speed and comfort. Here we discover how and when to perfect the aero tuck...
For many novice triathletes, their first aero upgrade is to bolt a set of clip-on aerobars to their road bike and expect chunks of time to fall off their bike split. Yet many find they end up slower and more uncomfortable. Road bikes have a different geometry to dedicated TT bikes and this has to be considered when fitting aerobars.
As Phil Burt, lead physiotherapist of the Great Britain Cycling Team and author of Bike Fit: Optimise Your Bike Position for High Performance and Injury Avoidance, explains: “A road bike and a TT position won’t be compatible unless you make a few more adjustments than simply clipping on a set of aerobars.
"Your normal riding position has to be rotated forwards for an effective aero tuck but without stretching you out too much and compressing your hip angle. The seat angle and top tube length on most road bikes make this hard to do. You’ll probably need to move your saddle forwards, maybe fit a seatpost that steepens the seat angle and obviously adjust your saddle height to accommodate these changes. At the front end, you’ll also probably need to consider a shorter stem to reduce reach. Once you have the position right, it’s then essential that you train in it and don’t wait until race day.”
Even if you decide on a dedicated TT set-up, being able to adjust the bike, especially the cockpit, to your position should be a top consideration. Many integrated systems don’t allow the range of adjustment necessary and, although they may look sleek, slippery and tempting, remember that more than 80% of
drag is down to the rider.
When the Zipp engineers were designing their Vuka bars, adjustability was their core consideration. Nathan Schickel, Zipp product manager, says: “From the inception of Zipp aerobars in 2006, the focus has been on adjustability to allow the rider to find their most comfortable aerodynamic position. Our designers know that not having a position you can stay in for your entire race is a wasted opportunity to go fast. Therefore, our focus is on ensuring the bars and bolts are as easy to adjust as possible.”
Although it’s important to train in your race position, there are times when hunkering down on your aerobars isn’t a good idea. Group situations such as club rides are an obvious example. Don’t turn up to sportives with them either, especially those run under British Cycling rules. With the International Triathlon Union (ITU) making some age-group championship races draft legal for 2016, some riders are going to find themselves in bunch racing situations with the option of using short aerobars. If you have any doubts about your handling ability, opt for a straight road set-up. If you do use aerobars, make sure they comply with the ITU regulations for draft-legal races.
Even in a race situation, don’t be a slave to your aero tuck. If the course is hilly, there’ll come a point during climbing when the increased power of sitting up or standing will outweigh the aero gains of using your aerobars. Even on closed roads, if you’re unfamiliar with a descent it’s better to lose a bit of speed and cover your brakes.