Popular to the commonly stated consumer belief in our shop sometimes, simple math could show you that the slowest people benefit more from improved aerodynamics. Depending on budgets, this could be a $145 – $200 dollar aero helmet, a Zipp carbon tubular wheelset, or a more aerodynamic bike. The logic can be shown by a well known formula (speed = distance / time). Before getting to the base of this mathematical argument, we first must recognize that aerodynamic advantage may indeed decrease as the rider’s speed decreases. When talking about riding speed, we must remember that we are talking about average ground speed. If for instance I am riding down a hill for a half mile at 25 mph into a 15 mph headwind the helmet is going to help a lot considering that I am really riding into a 40 mph headwind. So, when talking about average speed we must remember that half the riding time is spent above the ground speed and half of the distance covered will have some component of a headwind. Since an aerodynamic improvement does not make someone slower when riding below the average ground speed nor when riding in a tailwind, the aero advantage in the real world matches what wind tunnel results yield. Now that that is out of the way, lets address the heart of the issue. Most triathlon competitors would not argue with the fact that a mere improvement in aerodynamics will separate certain triathletes from the others in the lead pack. However, if you argue that the slowest athlete or age grouper actually picks up the most “free time” from an aerodynamic improvement such as an aero helmet, an argument may ensue.
However, if you take an elite cyclist that can ride a 40 km time trial course at a speed of 28mph, they will finish the race in roughly 53mins and 16 seconds. Now, if you place an aero helmet on that same rider, they have the possibility of picking up 0.5mph more in speed with this new piece of equipment (well within the range of aerodynamic advantage for an aero helmet). Now, this same rider traveling 28.5mph will finish 40km in 52 mins and 20 seconds. The time difference with this advantage is 58 seconds roughly.
Now an average age group rider that has other commitments may conceivably finish the course with an average speed of 18mph. This athlete will finish the 40 km time trial in 1 hour, 22 mins and 51 seconds. If this rider experiences a similar aerodynamic gain of 0.4mph gain by wearing an aero helmet (factoring in a slightly lower aerodynamic benefit due to average ground speed), their time over 40km would be 1 hour, 21 minutes and 3 seconds. They would shave 1 minute and 29 seconds off of their prior time with the same aero helmet, gaining 31 more seconds of “free” time versus the elite athlete.
With this being said, a simple formula can be easily used to show that the slowest athletes truly gain the most from improved aerodynamics. Next time you are looking at an aero helmet, think twice before saying “I am too slow to wear something flashy or dorky like that!” First of all, no one is too slow to enjoy technological equipment improvements and the speed = distance/time formula will always point to a different side of the argument. If you want to smash your old personal records as an age grouper, strongly think about what products could make you more aerodynamic. Maybe that new full carbon wheelset or a new aero helmet is in the cards for this season!