How to choose the right cycling helmet for race-day

On race-day, your choice of cycling helmet can have a large influence on your triathlon performance. 

The fastest option could save you minutes over longer triathlon distances. Equally, a poor decision in hot conditions could lead to disastrous overheating and dehydration. 

From the range of aero, road and TT helmets available, in this article, we’ll explain which type is best for which races. 

Time-trial helmets

Although the best time-trials helmets are generally the fastest type for triathlons, the pros rarely race in them these days. 

This is because they’re hot and the best aero helmets are usually better ventilated and almost as aerodynamic.

However, if you own a TT helmet, it still might be worth wearing it if cooler conditions are forecast for race day. 

Aero road helmets

The fastest aero road helmets only give away a handful of watts to heavier and hotter TT helmets. As a result, they’ve become the default race-day cycling helmet choice for pro triathletes.

If you buy one helmet, make it an aero helmet. Unless you ride in the hottest conditions, you’re unlikely to overheat. And in winter, fewer vents are welcome. 

Compared to the best road bike helmets for triathlon, modern aero helmets are much more aerodynamic. We’ve calculated that an aero helmet can save you 44 seconds over a 40km bike leg, making it one of the best ways to get more aero on a budget. 

Meanwhile, aero helmets are barely heavier and not much less cooler than traditional vented helmets. 

Road bike helmets

All this is not to say road bike helmets don’t have their place in triathlon. After all, the key thing is that a helmet meets the relevant safety standards. The best budget bike helmets will protects your head in the event of a crash.

Unless you’re targeting a fast triathlon time, if you already own a road bike helmet, it’s probably not worth upgrading to something more aerodynamic. 

But when the road points up, such as in the Alpe d’Huez triathlon, a road bike helmet will be your best race-day cycling helmet choice.

When the gradients top 8%, weight beats aero and ventilation is essential. The temperature during the summer in the Alps or Pyrennees can become almost unbearably high. 

If you do descend in a mountainous triathlon, you’ll likely be going as fast as you’re comfortable to go. Therefore, an aero helmet won’t help unless you’re sat on the top tube and hugging your stem at 60mph.