Do I really need an aero helmet? How much time could I save by wearing one and are they worth using in all conditions?
CHRIS FELLOWS, EMAIL
JOE BEER
is a multiple winner of 220’ Coach of the Year award
The short answer is no. And that’s partly because what an aero helmet is considered to be has changed. It’s no longer a simple choice between vented, ‘brick wall’ helmets or super-slick, ‘long-tail’ time-trial options. The former cools better but saps speed; the latter enables speed gains but can lead to your head overheating.
Geeks like myself will have noticed that Sebastian Kienle used the vented Scott Cadence helmet at 2016’s Ironman Hawaii. But he was still able to post a suitably stunning bike split and run well enough to take a superb second place behind Jan Frodeno. At a special Scott Associates event last July, I found out that engineers had already planned for Kienle to use a Cadence helmet, as they’d got its drag within 4 watts of his usual Scott Split helmet. But perhaps more importantly, the Cadence had significantly better cooling to reduce temperature build-up prior to the run. Et voilà, a ‘road helmet’ that’s aero and cools! In Kona the latter is more important than total bike drag, although Scott did tweak Kienle’s Plasma in order to account for the difference, so his drag numbers may have ended up exactly the same.
The penalty a ‘bad’ road helmet might actually cost you compared to a vented aero road helmet is probably 10-15 watts, which equates to 5-6mins over 180km, so aero is obviously still of great importance. But if you’re a bigger athlete, you won’t dissipate heat as well as the smaller guys/girls and will need to take on more energy. If that’s the case, you’ll probably want to make getting off the bike cooler a priority.
If you can afford it, having multiple helmet options may be a good idea to cover different race distances and conditions. But your priorities should be a great position and great clothing. Only after you’ve sorted those is it worth trying to reduce drag as far as your finances and physical abilities allow.