As coach and sports scientist Garth Fox explains, if you’re a time triallist, your number one enemy is aerodynamic drag. It is always present and will always be working against your attempts to go quicker.
Your bike accounts for around 20 percent of the aerodynamic drag that you encounter, the rest is down to your shape and your frontal area – the part that hits the wind.
To a certain extent, Fox says, this means you can buy ‘free speed’. Things like aero bars, aero helmets and tight clothing all contribute to better streamlining. They optimise air displacement and minimise the low pressure area formed in your wake, resulting in less drag.
An aero helmet can be a cost-effective upgrade compared to, say, an aero-tubed frame. And as there’s often little to choose between aero helmets in terms of aerodynamics, it can easily come down to what’s comfortable.
The helmets below have all been rated with four or more stars in Triathlon Plus magazine over the last few years, and cover a wide range of price points. Read on to find out which will work best for you.
£169.99 / US$250
The large channels and vents do a decent job of keeping the heat down without sacrificing aerodynamics. It’s easy to put on in a hurry, and a long, sweeping tail and close-fitting sides help keep the drag down to a minimum.
Bell Meteor II
£129.99 / US$N/A
This Bell Meteor II has an easily adjustable cradle with decent pads, 10 vents mean you don’t overheat and it’s light enough (410g for a medium) that you can hold your head up to get the helmet tail against your back without extra strain.
Limar Speed Demon
£144.99 / US$200
For hot weather racing, the Speed Demon is an excellent option. There are six front vents, three exhaust ports, and even the ear fairings are ventilated. It’s a light helmet, too, weighing just 359g (11g less than claimed).
The range of adjustment is another strong point, thanks to a cradle which can be rotated as well as tightened. That’s just as well as there’s only one size available (54cm-61cm). Downsides? The ear fairings feel flimsy and if you have a very large head the Limar is a squeeze. Good to go when the going gets hot.
£169.99 / US$180
It’s easy to forgive the Tardiz its somewhat daft name when it’s packed with features. The Rollsys dial on the top of the helmet makes for quick and easy fit adjustment, tensioning a cable around the whole of the head, not just a cradle at the back.
The chin strap uses a quick and easy magnetic fastening, and there are enough air vents to take the edge off when you’re out on a hot bike leg. A golf-ball-style dimpled finish on the back of the helmet is claimed to deliver further aero gains. An innovative and comfortable aero helmet.
£119.95 / US$188
It shouldn’t count for much, but the TriBase certainly looks fast, with its long tapered tail and smooth lines. For an aero helmet it’s impressively light, weighing in at 333g for in the large size (55-61cm), just 1g heavier than claimed. Four front vents provide some cooling for hot days, but don’t expect much air to get through such narrow slots.
A rotary dial adjusts the cradle to fit the back of your head, and a padded flap stops the clip rubbing under your chin – a nice touch on a basic but good value helmet. A light and inexpensive aero lid.
£129.99 / US$160
It’s unusual to find a visor on such a reasonably priced lid – a feature which should help the Chronometro cut through the air smoothly. Fit is adjusted by moving the straps and the rear cradle along stretches of Velcro. It seems rather unsophisticated compared with the likes of the Laser Tardiz, but it does the job.
However, the LAS is relatively heavy (524g, 74g more than claimed) and with no front air vents you’ll soon be sweating hard on a hot day which may make longer races uncomfortable.
£179.99 / US$200
It comes with a detachable visor with small breathing holes in the top, two main front vents and one rear, a stubby tail (open underneath) and a fully adjustable internal cage. We liked the range of options that gave us: three different tilts plus the ability to loosen or tighten on the fly.
Catlike Chrono Aero Plus
£149.99 / $US300
This Catlike aero helmet isn’t new, but with such a strong pedigree, including a time trial win at the Giro D’Italia, we couldn’t resist testing it. While many of the latest aero lids are full of groundbreaking features, this one is more basic – but no less effective.
Louis Garneau Vorttice
£159.99 / $US249.99
Louis Garneau have started adding all manner of innovations to stay ahead of the competition. The Vorttice is light, breathable and easy to adjust, although it’s one of the most bulbous aero helmets we’ve seen. And it comes with a visor, which also saves watts.
£299 / US$499
The Bambino is a very nice helmet in many ways. It's one of the most comfortable we've ever tried, fitting snugly but not too tightly, and covering most of your face, including your ears. The leather chin strap is a classy touch.