Best aero helmets for triathlon in 2024

The popularity of aero road helmets has exploded in triathlon, sending the long-tailed TT helmet towards the margins as savvy triathletes have realised that aerodynamics, comfort and ventilation could come in one helmet package.

You’ll still see both on the race track, of course, so read on for our reviews of a range of top aero road helmets and TT-style helmets.

On this page, you’ll also find our guide to what an aero road helmet actually is, and an overview of how we tested (in and out of the wind tunnel). It may also be handy to read our guide to helmet certifications before getting started on the below, too.

As an aside, if you’re looking for more aero gains, take a look at our list of the best clip-on aerobars.

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Tried and tested: Best aero helmets at a glance

• Best aero road helmet for triathlon: Specialized Evade 3 | Buy now from Tredz
• Highly rated: HJC Furion 2.0 | Buy now from Saddleback
• Best aero road helmet for those on a budget: Van Rysel Road Bike Helmet FCR | Buy now from Decathlon
• Best ventilated aero helmet: Giro Eclipse Spherical | Buy now from Tredz
• Best aero road helmet for pure speed: Scott Cadence Plus | Buy now from Alpinetrek

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Best aero helmets for triathlon as tested in the wind tunnel in 2024

Giro Eclipse Spherical

• Price: £239.99 / $250

Giro launched the aero road helmet movement in 2012 with the Air Attack, so any launch from the brand demands attention. So it is with the Eclipse Spherical.

The Roc Loc 5 Air system’s internal fitting mechanism and slick retention dial swiftly secures an optimum fit, while the plush yet lean Ionic+ padding sits in the perfect place on the forehead for comfort and sweat mopping.

The Eclipse boasts 14 ventilation channels and breathability felt good.

Admittedly, it wasn’t among the best performers in our wind tunnel testing in May 2024, coming eighth out of 11 at both 30km/h and 40km/h (with a yaw angle of 7.5° and a rider on tri-bars). That said, it’s still likely to have the edge over standard road helmets.

The Spherical tech may be the most effective integration of MIPS (Multi-directional Impact Protection System) I’ve seen and the outer shell is smoothly integrated into the EPS core to complete a classy look.

The 277g weight’s decent enough, but that and the wind tunnel results, is all that’s mid-table about this low-profile, tech-laden helmet.

Read our full Giro Eclipse Spherical review for more.

Met Manta MIPS

• Price: £220/$299

The Met Manta MIPS has a tri-friendly magnetic buckle, which is great for quick transitions. 

What’s not so great is the excess straps, which feel counterproductive given the efforts that’s gone into improving aerodynamics elsewhere. 

Safety is boosted by MIPS, but the helmet hasn’t yet been tested by the Virginia Tech institute as of June 2024. 

The lid offers plenty of comfort and the rear cradle delivers a decent 3.5cm of vertical adjustability. The retention dial is easy to adjust on the go, too. 

Venting’s fine for an aero helmet and 251g is very impressive. In the wind tunnel, the Manta MIPS outperformed our baseline Decathlon helmet, being 31.8secs faster over a 40km bike leg at 30km/hr and 9.2secs quicker than it when riding at 40km/hr.

See our full Met Manta MIPS review for more.

HJC Furion 2.0

• Price: £180

HJC’s Selfit retention system takes some getting used to, but I grew to like. The internal adjustment mechanism is decent, but I’d like to see more padding on the front for long-distance racing.

There’s no MIPS or Virginia Tech rating, but there is an internal frame integrated into the EPS form for reinforcement.

In the wind tunnel the Furion 2.0 was 18.6secs faster than our baseline Decathlon helmet at 30km/h and 19.4secs faster at 40km/h. The latter makes it the second fastest helmet tested by 220 in 2024 at that speed.

A weight of 216g is class-leading.

Read our full HJC Furion 2.0 review for our full verdict.

Specialized S-Works Evade 3

• Price: £250/$300

The Evade 2 scored well in our tests previously (see below), and Specialized says that the Evade 3 has ‘maintained’ the aero performance of its predecessor, while increasing ventilation with nine vents.

Honestly, it strikes the sweetspot between speed and breathability superbly.

On the downside, I’m not so keen on the Tri-Fix web strap system, which feels uncomfortable under the ears.

The helmet boasts a MIPS Air Node liner and scored a five-star rating by the Virginia Tech institute’s helmet lab.

A weight of 275g is about standard and it’s tidily finished.

In the wind tunnel it was 31.8secs faster over 40km at 30km/hr than our baseline Decathlon helmet and 10secs faster at 40km/hr. Both results put the Evade 3 in the top half of the 11 helmets we tested.

Find out more in our full Specialized Evade 3 review.

Abus GameChanger 2.0

• Price: £260

I found the original GameChanger too narrow and uncomfortable. Thankfully, the sequel is a step-up thanks to the slighter wider fit, albeit it’s still quite narrow so wide-headed cyclists beware.

It employs the MIPS Air Node safety system and received a five-star rating at the Virginia Tech institute for helmet safety, though you can also buy a non-MIPS version for £225.

With a large array of forward-facing airflow channels, airflow is impressive for such an aero-focussed helmet.

The Fidlock magnetic buckle is great for triathletes, as it’s effortless and swift to connect or undo.

Weight is 284g, while in the wind tunnel it was 27.3secs faster over 40km than our baseline Decathlon at 30km/hr and a 14.4secs faster at 40km/hr.

See the full Abus GameChanger 2.0 review for more.

Scott Cadence Plus

• Price: £242.98 / $242.98

A standout of the Cadence Plus are its Aero Plugs or winter bungs (an extra £12.99), which can be shoved into the ventilation channels on colder days or if you’re seeking an aero advantage where heat isn’t a major consideration.

The Cadence Plus features an exceptional internal adjustment mechanism that was instantly secure and easy to adjust.

Internal comfort is high thanks to some great padding and this sits atop of the MIPS Air Node system.

Against our baseline Decathlon helmet the Cadence Plus was an enormous 53.8secs faster over a 40km bike leg at 30km/hr and 39secs faster when riding at 40km/hr.

Meanwhile, the helmet scored four stars in the Virginia Tech institute’s safety tests.

It weighs 284g weight, increasing to 338g with the bungs in place, which is a little on the heavy side, but it’s wind tunnel performance was impressive.

Worth noting, though, is that the tests were conducted with the bungs in place, but it’s performed well in previous tests without bungs.

See our full Scott Cadence Plus review for more detail.

Van Rysel Road Bike Helmet FCR

• Price: £89.99

What a treat from Decathlon – an aero road helmet for less than £100. There’s plenty of tri appeal in the Road Bike Helmet FCR.

For one, there’s a magnetic chin buckle, which is easy to use with chilly fingers.

The aero performance was also reasonable for a helmet at this price point. Yes, it was the slowest out of the 11 helmets tested in the wind tunnel at speeds of 30km/h, but at 40km/h it outperformed the Kask Elemento by 5secs over a 40km distance.

There’s no MIPS nor any rating from the Virginia Tech institute, but it does comply with European regulation EN1078.

Ventilation is reasonable, while I was a fan of the slightly wider fit, too.

A weight of 290g isn’t ideal, but isn’t particularly noticeable while on the road.

Getting the right fit is easy enough and comfort is decent, too, making this a great value option.

Find out more in our full Van Rysel Road Bike Helmet FCR review.

Smith Ignite MIPS

• Price: £229/$250

The Smith Ignite MIPS has a lot going for it, including great safety features.

The helmet uses Koroyd material inside the two main vents for impact protection and energy absorption, but it also keeps bugs out.

You also get the MIPS brain protection system, which is great to see.

In the wind tunnel in May 2024, it was the second fastest aero road helmet out of 11 on test at 30km/h, though it was seventh out of 11 at 40km/h.

There are six vents on the front of the helmet, but these struggled when it came to airflow on hot days or hilly courses.

The padding proved comfortable, but getting the split straps to sit flush against my face wasn’t easy.

Weight is 283g in a size medium.

For more detail see our full Smith Ignite MIPS review.

Kask Elemento

• Price: £335

There’s no conventional padding here. Instead, the Elemento uses a Multipod beehive material located internally at the top of the helmet. It’s job? To keep the helmet away from the skull to improve airflow, which it does effectively.

The retention dial works well, but for the money I’d like to see the brand’s luxurious leather chinstrap of previous models. The basic buckle included here proved difficult to connect in haste.

There’s no MIPS here, but the helmet has gone through Kask’s WG-11 Rotational Impact Test (which has also been used by Rudy Project for the Nytron).

In the wind tunnel the Elemento didn’t fair too well against the other helmets on test coming toward the back of the pack, but this helmet does feature a lot of ventilation. Plus, Kask’s Utopia range would be the more aerodynamic pick from the brand.

See the full Kask Elemento review for more.

Oakley Aro7

• Price: £272 / $260

The latest Aro7 offers broader appeal than its predecessor, which was time-trial-focussed.

That’s good news, but the loss of the magnetic chinstrap isn’t, making it more of a faff. Finding an ideal fit is otherwise easy enough.

There’s limited venting on offer here, while the wind tunnel performance was middling.

The Aro7 was just 2secs faster than our baseline Decathlon helmet over a 40km bike leg at 30km/h, and was 4secs slower at 40km/h.

That said, in the interest of consistency, the helmet was tested with the same sunglasses as the other helmets were tested with, rather than with the helmet’s dedicated visor, which is likely to have improved performance here.

Speaking of which, the included clear and tinted Prizm visors offer plenty of clarity and fit securely to the helmet.

A weight of 370g (including visor) leaves a little to be desired, though.

See our full Oakley Aro7 review for more.

Rudy Project Nytron

• Price: £189.99 / $324.99

Swiss Side are one of the most celebrated aero experts in cycling, and the Nytron here is a collaboration with their no-stone-unturned tech team and Rudy Project, themselves no lightweight in the aero arena.

The wind-tunnel development is evident in the aero tail and 15 stealthy exhaust ports, the latter making this one of the most vented and versatile lids here for a variety of tri situations.

Thankfully, in our independent wind tunnel testing, that development was there for all to see, placing third out of the 11 helmets tested at the time at a speed of 40km/h.

It’s one of the cheapest aero helmets around, but is still expensive, which makes the cheap plastic casing on the ratchet system an unwelcome surprise that’s already showing signs of wear.

The padding, straps and retention system are all unflashy but functional.

MIPS is missing, but there’s Rudy Project’s WG11 rotational impact system. Weight is a decent 268g.

Read our full Rudy Project Nytron review for more.

Table: 2024 wind tunnel test results

Take a look at the table below to see a breakdown of which helmet was fastest over 40km. The times are shown in seconds, with the testing conducted with a yaw angle of 7.5° and at two speeds, 30km/h and 40km/h.

Testing was done with the same rider in the same aerodynamic position on aerobars. Read more about how we tested further down this article.

Helmet	Time (secs) @ 30km/h	Time (secs) @ at 40km/h
Van Rysel Road Bike Helmet FCR	4799.99	3599.99
Oakley Aro7 (without visor)	-2.16	+4.34
Kask Elemento	-3.49	+5.19
Giro Eclipse Spherical	-11.44	-0.18
HJC Furion 2.0	-18.63	-19.44
Abus GameChanger 2.0	-27.30	-14.42
Rudy Project Nytron	-30.69	-15.27
Specialized Evade 3	-31.80	-10.01
Met Manta MIPS	-31.84	-9.17
Smith Ignite MIPS	-34.41	-9.14
Scott Cadence Plus (with bungs)	-53.78	-38.98

Best aero helmets tested in the wind tunnel pre-2024

Limar Air Speed

• Price: £148

Limar has made a concerted effort to move into the triathlon market in the last couple of years, attracting British ITU racers into the fold and adding a magnetic buckle on the chinstrap for added transition appeal for cold, post-swim fingers.

Limar’s own positive tunnel testing has only extended to athletes riding on the hoods.

Our tri-bar Boardman tunnel analysis, however, confirms that this is one swift lid, regularly coming second behind the S-Works Evade II or Giro Vanquish MIPS (especially at the key 45km/h speed and 0° yaw angle).

In terms of safety, there’s no MIPS protection (you can now choose a model with it included, though) but the retention system is secure, while venting from the 12 channels on hilly, sticky days is acceptable. Weight is a decent-enough 259g.

Specialized S-Works Evade II

• Price: £200

Specialized has spent plenty of time in its own Californian wind tunnel with the Evade II and our own Boardman tunnel results reaffirm this aerodynamic development.

The Evade was the fastest overall on test in our Boardman tunnel sessions, especially at the speed of 45km/h, but impressive across a range of yaw angles.

The 12 deep, internal air channels are an improvement over the original (as is the new addition of the MIPS safety system) for warmer high-intensity riding, and the magnetic buckle is great for transition speed and numb finger use.

Weight with the MIPS safety system is still a lean 262g but I’d prefer more adjustment with the side straps, which are oddly fixed in place.

The Evade II has recently been superseded by the Evade III, but you may still find the older model floating around at retailers.

Giro Vanquish MIPS

• Price: £249.99 / $300

The Vanquish MIPS is unique among the competition here as it comes with a magnetic Shield Visor.

The visor provides good clarity but there’s a clear gap between that and the face, giving me concerns about detritus flicking up.

That’s a shame, as the helmet offers sound ventilation via its 10 well-placed vents, there’s MIPS (Multidirectional Impact Protection System) and comfort from the Roc Loc system (the buckle is fiddly, however).

Our Boardman wind tunnel results saw it regularly come behind only the S-Works Evade II.

It excelled at 0° yaw angle and 35km/h speed, but was even better in an aggressive aero position.

Despite the 355g figure, it doesn’t feel like a weighty lid when riding. It does have a very high RRP, however.

Van Rysel Racer

• Price: £39.99 / $89.99

Largely blown your triathlon budget on a race spot and flights to Ironman Lanzarote?

Then you could do far worse than picking this forty quid Decathlon creation as your lid of choice, given it offers fine ventilation and superior aerodynamics in crosswinds.

While it performed poorly at 0° yaw angle (i.e. into direct headwinds), the wider the wind angle, the better the Racer performed.

Our recorded segments even showed it beating the S-Works at 20° yaw angle when riding at 45km/h.

The ventilation is amongst the best on test here yet it loses marks due to the firm front padding, a tricky to adjust retention system and straps that have a tendency to loosen.

I also prefer the other four available colours.

Kask Utopia

• Price: £245 / $300

When we reviewed it, the Utopia was the helmet of Team Ineos and the official helmet of Ironman Europe, the former suggesting exhaustive R&D, the latter a huge marketing pot.

And it’s the R&D we’re interested in here, with the Utopia reaching the promised land in our 2020 Silverstone Sports Engineering Hub tests – beating both Smith (easily) and Spiuk (much closer) at every speed and yaw angle.

Onto the asphalt and I’m a sucker for Kask’s leather chinstraps, while the multi-directional ratchet system and thick internal padding aid both fit and comfort.

Ventilation via the nine vents is only satisfactory and I’d like a horizontal pad across the forehead to prevent sweat streaming down. Weight is a lean 235g.

All that being said, it’s hard to pick up a model of the original Utopia these days. It’s since been replaced by the Utopia Y, which sees the addition of the brand’s Octofit+ system and Resistex Carbon padding at the front.

Smith Trace MIPS

• Price: £219.99 / $260

Of all the helmets on test here, the Trace is the most confidence-inducing when it comes to safety.

That’s due to both the MIPS and Koroyd beehive core, also seen on helmets from Endura and, to a greater extent, the custom 3D-printed offerings from Hexr.

It’s the helmet that I’ve got the most usability out of, joining me on both trail rides and road slogs.

It’s durable, the ratchet is efficient and the internal pads are plump.

Anecdotally, I found midsummer ventilation compromised by the beehives.

Plus, despite Smith’s claims of aero dominance from testing in 2018, it was consistently out-performed by both the Kask and Spiuk in our late 2020 Silverstone wind tunnel tests at every speed and yaw angle.

Spiuk Profit Aero

• Price: €129

Given the brand made my first-ever tri-suit, I’ll always have a place in our tri heart for Spiuk.

If its UK triathlon exposure has reduced since 2008, the Profit Aero comes with the backing of former ITU World Champ Mario Mola and with plenty of multisport flourishes.

These include a magnetic buckle and Boa retention dial for T1 speed, while the brand’s aero focus has produced a helmet that delivers in the wind tunnel, coming only marginally behind the twice-the-price Kask (especially at 0° yaw angle).

The nine vents are effective enough, but the limp padding and frustratingly fiddly straps show where some cost compromises have been made.

Only two available sizes also limit the chances of perfecting your fit.

Best aero road helmets we haven’t tested in the wind tunnel

Kask Nirvana

• Price: £320 / $400

The Nirvana debuted on the heads of Ineos Grenadiers in 2024, with the Italian brand making plenty of lofty aerodynamic claims (35% more aero than the competition) about its new top-end aero helmet, without showing us the evidence. 

Onto the head and it’s light (276g for a medium) for such an aero-focussed lid, with the unique ear tips likely to offer both speed and safety advantages… although the confined space here might well cause discomfort for those with larger ears. 

The comfort offered by the internal Multipod padding, Kask’s lovely faux leather chinstrap and the Octofit retention system is excellent, while the airflow from the sizeable ventilation channels is impressive for a minimally vented lid. 

Where it suffers is on muggy days and at slower speeds, with the padding sub-par at storing sweat and not what I’d demand from a helmet with a £320 price tag. The front also crept into my line of vision when using tri-bars.

Kask Wasabi

• Price: £269 / $350

The USP of the Wasabi is its billing as a year-round helmet, with an easily adjustable vent allowing riders to block or open the forward-facing channels, while a dense Merino wool lining adds warmth and wicking properties.

This ticks the winter boxes but, for summer, there are better ventilated options out there (and, admittedly, a £15 Merino skull cap is a far cheaper alternative in winter), even if the closed vents enhance the aero profile.

Elsewhere, it’s classic Kask, with a luxurious leather chinstrap, the outer shell slickly covering any exposed EPS foam, and a hugely effective retention system.

MIPS is eschewed in favour of Kask’s WG11 system, weight is an acceptable 272g, but that price tag and winter focus just make this too niche.

We’re also yet to put the Wasabi to the test in the wind tunnel.

Abus GameChanger

• Price: £189.99

The GameChanger is about as aggressive as an aero road helmet gets and has been around since 2017, but will the lid age better than its name? It’s always been divisive and that still stands in 2023. 

The good is its extreme aero road focus, with rear thermal ports and a similar build to S-Works’ long-standing Evade series, which 220 wind-tunnel tests have proven to be best in class.

The 263g weight is decent enough for a lid with limited ventilation channels, while the ventilation is also satisfactory for something so speed focussed.

And, while it’s a cliché to rival the term game changer, it’s a helmet that does feel fast on the roads (though we’ve never tested it in the tunnel to validate this). 

But it’s under the lid where the GameChanger really struggles, with minimal padding, a bare polystyrene interior and an ultra slim fit that saw wedges of exposed EVA foam digging into our skull.

The ratchet system and straps also feel pretty basic for the £190 outlay, meaning it’s high time Abus delivered a sequel, which the brand has, so watch this space for a review.

Abus GameChanger Tri

• Price: £399 / $599

The GameChanger Tri lives up to its boastful title – here is a lid that looks like few others, with a vast ventilation channel on the top adding a Star Wars vibe.

The design wraps itself around the face in a streamlined manner to produce an exhilarating ride feel, with the straps also sitting flush to minimise drag.

The magnetic visor is easy to install and remove, but lacks the function to magnetically stow upside down like the Endura and Oakley.

Clarity is excellent, as is fog prevention, although the shell extending over the ears does add weight (362g with visor, 324g without).

Those with round heads can struggle with Abus’ standard GameChanger (reviewed above), but this version feels wider and comfier, even if taking it off swiftly in T2 is slow and a little painful. 

Kask Bambino Pro

• Price: £285 / $420

One of the things you instantly notice when putting on the 340g Bambino Pro is how the ear coverings numb the senses, especially in regard to traffic noise if you’re racing on open roads.

Yet there’s a welcome level of internal comfort that’s lacking in the Abus thanks to its dense 5mm padding, while Kask’s faux leather chinstrap always impresses.

The lack of a full-length tail adds versatility and less of an aero penalty if you move your head, with Kask promoting how the Bambino Pro, ridden by the INEOS Grenadiers WorldTour team, is aerodynamic in a variety of head positions (though we’ve yet to conduct our own wind tunnel tests on this model). 

A choice of visors offering unrestricted vision are available, with my clear set staying mist-free on some sweaty hill sets in early summer.

The magnetic clips mean flipping it upside down is easy but doing so blocks the exhaust ports. And ventilation is where this Kask, like all TT lids, suffers when compared to vented road helmets.

You’ll need to ask yourself if the extra time saved by going for a TT over aero road lid (our tunnel tests suggest a saving between two and six minutes over 180km) are worth the danger of overheating.

If you go down the TT route, then this lid ticks the speed and internal comfort boxes. Just remember to practise putting it on/off at speed before race day (removing the visor helps).

Endura D2Z Aeroswitch

• Price: £399.99

The rise of aero road helmets has seen TT helmets nudged to the tri margins since 2012.

Endura counteract this by providing the 2-in-1 Aeroswitch, which has a removable tail section so it can be used as both a TT and aero road helmet.

A full-scale R&D process with acclaimed aerodynamicist Simon Smart suggests the drag testing has been exhaustive (though we’ve done no wind-tunnel testing of our own).

Adding and removing the tail is simple, while the included visor is securely attached with magnets and provides excellent visibility. It can also be stored upside down like the Oakley.

The helmet’s core is Koroyd, a mesh-like material that’s said to offer improved impact protection over EPS foam and seems to help ventilation.

Yes, it comes at a price, but you’re getting two helmets in one.

We’re proud to say that we’re one of the only publications worldwide to regularly test our aero helmets in the wind tunnel.

The reason is that nearly every brand claims to produce the world’s fastest helmet, but still refuse to release the raw tunnel data from their own tests.

As our wind-tunnel results show, some helmets only perform at certain angles and speeds, so, while a helmet may technically be the fastest at a 20° yaw and riding at 55km/h, that doesn’t mean it performs across a range of wind directions and riding speeds.

Given that the vast majority of a 180km Ironman bike leg is spent riding below 10° yaw (98% at IM Arizona, 72% at Kona, for example), the 0°, 7.5° and 5° angles especially were the key focuses for us.

2024 wind tunnel testing

Our most recent wind tunnel testing took place at the Silverstone Sports Engineering Hub in May 2024 under the supervision of aero expert Stephen Roche (AKA, The Bike Tailor) and wind tunnel engineer Nick Richards.

This test was conducted with a yaw angle of 7.5°, which is often used as a real-life baseline, as it’s consistent with what you’ll find out on the road.

We used the same rider, tri-suit and sunglasses throughout the testing, and ensured the model kept the same position for each test by making use of the wind tunnel’s rider outline guides.

These allowed us to keep an eye on the rider and ensure he didn’t deviate from a consistent position on his tri-bars.

Power was kept consistent throughout testing at 150w, and we tested at both 30km/h and 40km/h, capturing 100 data points every second and recording each run over 30secs to get an average CdA.

Previous wind tunnel testing

In addition to our Boardman wind-tunnel tests from 2019 and our testing in 2024, we aero-tested the Kask Utopia, Smith Optics Trace and Spiuk Profit Aero at the Silverstone Sports Engineering Hub with The Bike Tailor in 2020.

We tested each at yaw angles of 0, 5 and 10°, and at speeds of 35km/hr and 45km/hr on a triathlon bike with the mannequin for added reliability.

There are also some helmets reviewed below that we haven’t been able to test in the wind tunnel, and we’ve made clear which ones these are.

A key aspect in our testing criteria is ventilation. An aero road helmet should also provide better ventilation than a TT lid in summer racing and, as our year-round testing has proven, some protection from those beastly easterly winds in the winter.

Other key factors are the effectiveness of the retention system for comfort and fit; the ability of the buckle to be unclipped (especially with cold post-swim fingers); and the helmet’s often-overlooked modus operandi, safety.

All of the helmets here have passed the relevant European bike helmet safety tests, but also look out for added safety features such as the MIPS system.

What is an aero road helmet?

While the weight of an aero road helmet is typically higher than a standard road helmet, our wind-tunnel tests at the Silverstone Sports Engineering Hub in late 2020 and at the Boardman Performance Centre in 2019 have shown an aero road helmet can be 3:22mins faster than a vented lid over a 180km Ironman bike leg, a healthy saving for those vying for age-group honours.

Much of this, of course, depends on an athlete’s ability to keep their head in the same aero position, but the drag penalties of moving one’s head aren’t as high on an aero lid as when riding in a TT helmet.

Aero road helmets will generally have had more development in the wind tunnel than standard lids to ensure they slip through the air more smoothly, so you may see less ventilation on offer.

They’re also different to out-and-out triathlon or TT helmets, which often have a teardrop shape and a tail at the rear.

These are typically more aerodynamic, but they do come with a weight penalty, offer less ventilation and can suffer on windy days.