Cycling aerodynamics Q&A: how can I reduce drag on the bike section?
220 cycling coach Nik Cook advises a triathlete in his second season on how he can make aero improvements on the bike
Q This year will be my second season in triathlon. I’ll be competing in Olympic and middle-distance races, and am looking to make some aero improvements. Should I buy a long-tail aero helmet or make upgrades elsewhere? (John McClean, email)
A If you’re heading into your second season, it’s unlikely your riding position is optimal and this is what you should focus on first. This doesn’t have to mean forking out on expensive wind-tunnel sessions, as there are cheaper alternatives. Aero Coach offers velodrome testing or, if you have a power meter, there are several DIY protocols you can follow on the road.
A lower tech option is to set yourself up on your turbo, take a head-on shot and try tweaking your position to reduce your frontal area. Then, use a side-on shot to try and flatten your back. Remember, though, aero is only one part of the equation. Don’t make your position so extreme that you’re compromising your pedalling power.
When you’re happy with your position, look for some more low-hanging aero fruit. Is your tri-suit tight and crease free? Have you minimised clutter, such as unnecessary bottles and food boxes, on your bike? Are your legs shaved? Seriously – Specialized tested the difference between shaved and non-shaved legs in its wind tunnel and found it was worth 70secs over 40km!
Wheels can make a big dent in your bike split, and your bank balance. For all but the most hilly bike courses, a deep-section front wheel and a disc on the rear will be the fastest combination. Look for second-hand deals or even consider the budget option of a cover for your rear wheel. It won’t make the same cool ‘whooshing’ sound of a real disc but will save you a measurable amount of time.
With regard to your original question – yes, an aero helmet can provide one of the best ‘bang for your buck’ aero gains. But unless it complements your position, it could end up costing you time. The tail of the helmet should smooth the airflow from your head on to your back, with a minimal gap in-between. If you tend to drop your head or move it a lot, a long tail will just stick up into the wind.
Try different helmets, take some side-on pics and don’t forget to factor in fatigue when altering your position (your head may move when you’re tired, thus affecting the aero benefits of the helmet). Also, aero helmets can be pretty uncomfortable in the heat if you’re prone to overheating, so any aero gains can easily be outweighed by the potential time losses caused by a boiling head...
Found this useful? Check out this article on how to find your most optimal aero riding position
For some advice for achieving a faster bike leg read former World Masters Cycling Champion and triathlon coach Dr Auriel Forrester article on increasing bike power here