Bike and cycling kit manufacturers are really promoting the aero benefits of their equipment and introducing a lot of lines with aero benefits at the moment. You could spend a lot of money making yourself more aero, but which items are likely to give you the best aero benefits for their cost?
To find out, we headed up to the De Havilland windtunnel at Glasgow University, part of the National Windtunnel Facility. Along with Visualbikefit.com, it’s developed its expertise in testing cyclists and their kit for their aero efficiency.
Ben started out in a standard vented helmet and relaxed fit jersey and shorts, which he gradually swapped out for more aero kit. Each time, his drag was measured for a minute with the wind tunnel running at 47kph, using highly accurate strain gauges attached to the platform on which he was pedalling.
In his starting kit, Ben would have to put out about 400 watts to overcome wind resistance at this wind speed, but by the end of the changes he’d saved around 50 watts. The largest gain came from swapping from the jersey and shorts to a skinsuit, which saved over 30 watts.
Swapping to an aero bike saved seven watts, whereas changing from 30mm deep aero wheels to 55mm deep aero wheels did not show a saving in drag at zero yaw angle.
But the lowest price per watt saved came from covering up the buckles and vents in Ben’s shoes with a pair of aero overshoes. Although the power saving was lower than a skinsuit, at 18 watts, the lower cost of the overshoes makes this the biggest gain for your buck.
We’ll be publishing more windtunnel videos over the next few months, so look out for more marginal – and not so marginal – gains to come.