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TT bike helmets: 7 of the best reviewed

7 of the best time trial aero helmets tested, rated and reviewed by our expert reviewer

In terms of seconds gained for pounds spent, a time trial aero helmet is potentially one of the best biking upgrades. However, before you head out and buy the most expensive and outlandishly profiled helmet available, think about the following points…. 

The helmet has to suit your riding position. There’s no point having a long-tailed helmet if you roll or drop your head a lot. The tail has to sit flat along your back or it can easily create rather than minimise drag.

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Also consider comfort; aero helmets often won’t deliver nearly as much ventilation as a conventional road helmet. That’s not an issue for spring UK races, but a major consideration at, say, Kona. Finally, don’t forget transition. A helmet has to be easy to get on and off and tweak on the move.

Here are 8 of the best aero helmets:


Lazer Tardiz 2 TT helmet


‘Like the Dr’s phone box it will help you move through space and time,’ say Lazer of their Tardiz 2, which we guess it kind of does, and at a much nicer price than their flagship Wasp TT. It’s distinguishable for the innovative Aquavent spring-loaded port that allows you to pour water in for cooling, channelled so the water filters down the back of your head. And in practice, this works a treat.

The retention dial is sizeable and just where you want it, and at the front there’s a conventional buckle with plenty of spare strapping to fit various head shapes (there are small, medium and large sizes). We found it tricky to get on quickly as the ear covers are pretty solid, so our first few T1 practice runs were a bit of a struggle. But for long-course tri, where those transition milliseconds are less crucial, the Tardiz 2 is good value and perfect for the job.

Verdict: a little tricky to get on but affordable, aero and loaded with tri features  86%

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Carrying a torch for more ‘traditional’ long-tailed TT helmets is Alpina’s Elexxion, weighing just 320g and slimmer in appearance with less frontal area than most modern TT helmets. Soft ear covers make it easy to get on and off, and for comfort there’s plenty of interior padding and a sizeable chin strap cover. The strap closure system is a self-locking plastic clip with a release button, which we found tricky at first but it’s no faster or slower than a buckle when you get used to it. The tail is long and quite horizontal, and no matter how hard we tried we couldn’t get it to sit flush with our back in the time-trial position. The Elexxion isn’t a bad lid, but it’s not quite as suited to triathlon as the other two helmets on test here. If you dabble in time trials, too, and can hold a steady head position in your multisport bike legs, it’s still a good buy.

Verdict: a decent long-tailed option but better for time trials 77%

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Taking both head positions into account, the S-Works TT from Specialized is the fastest helmet here. It was the most aero when head up and just 1.7 watts behind the Giro when in a deep tuck. That makes it versatile for different courses, riders and positions. It also has a very securely mounted visor that doesn’t impede transitions once you’ve got the hang of spreading the ear flaps.

Ventilation comes from the slats behind your ears and air to your face under the shallow visor; it works but is arguably designed more for TTs than triathlon and it wouldn’t be our first choice for a long, hot event. It’s fine on cool days, though, and, at 419g, it’s also the lightest here and is the only one to come in a travel case. It’s comfortable and stable, though it feels a different shape to other Specialized helmets, so try it on carefully.

Verdict: super-fast head up or down. Light, but pricey and less vented for warm riding 91%

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We’d understand if you were tempted to buy this helmet for the looks alone but before you do, at least read to the end. The Aerohead is well ventilated, with two ducts in the shell feeding internal channels to exhaust vents, and the fit is comfortable thanks to the RocLoc Air retention device and plush padding.

The wrap around lens – a Carl Zeiss item, no less – attaches very securely with magnets and can also be placed inverted above the brow to make transitions slick. It’s easy to reach up and place the visor one-handed. It also features MIPS for added safety at the cost of some stability on bumpy roads. Best of all, the Aerohead was the outright fastest helmet when in an aggressive position, edging out the MET and S-Works. However, head up it was plum last, 7.4 watts back, it’s prone to misting on damp days and it’s the heaviest here at 501g.

Verdict: a great visor, plush and,super fast, but only if you can get your head low enough 90%

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Continue reading our guide to this year's best TT helmets (2/2)


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So, what does the heads-up/heads down position look like?

It would also be helpful in these comparisons to see a relative sheet of drag so we can compare helmets. The way I read this, the Lazer must have the best venting on earth.

It's only a little less expensive than the S-Works, much slower heads down, and only a little quicker than the Scott that isn't liked heads up.


To the staff: Why would you go to all the trouble to test the drag of each of these helmets but then not let the reader see the numerical drag results for *all* the helmets in this article?

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