The Hedkayse One urban helmet folds down small for storage in a bag and is designed to survive multiple knocks and impacts, but is heavier than most other options and it's not especially well ventilated.
This Hedkayse One is far from your standard helmet. Rather than being made from expanded polystyrene (EPS) with a polycarbonate shell in time honoured fashion, it is largely constructed from a product called Enkayse, which is a flexible and fairly soft expanded polyurethane (EPU). Press your thumb into the Enkayse and you'll leave a slight dent that then disappears within a second or two.
"[Enkayse] manages the energy of impacts, so it can retain its integrity after more than one impact, large or small," says Hedkayse.
In contrast, expanded polystyrene liners are designed to crush in the event of a slam, so can only provide adequate protection for one impact.
"Because Enkayse dissipates energy rather than deforming on impact, it also cushions small bumps," says Hedkayse. "Polystyrene can't do this, since forces which are too weak to deform it are transmitted through. Enkayse provides comfort in protecting from small bumps. This may also have long-term benefits as researchers believe the cumulative effect of small knocks contributes to brain disease over time.
"Because Enkayse shrugs off little bumps, it means that Hedkayse One is durable against the knocks and scrapes that come with everyday use. You can be sure that Hedkayse One will stand up to the daily grind."
You're hopefully not bumping your head on a regular basis but the Hedkayse One is certainly durable and doesn't mind getting bashed around in the bottom of a bag when not in use. Pressure that would leave a permanent dent in an EPS liner has no long-term effect here; the Enkayse simply returns to its former shape.
The TAF (Tough and Flexible) outer shell, available in five different colours, is "a specifically engineered rip-proof military grade ballistic nylon" that's rugged enough to put up with plenty of abuse too. Cleaning with soapy water isn't difficult although the woven texture means it's not quite as simple as with a smooth EPS shell.
Hedkayse says that exposure to UV light can cause the colour of the TAF to fade or change slightly over time. We haven't experienced that, although you wouldn't expect to in our four-week review period.
We don't perform our own safety tests here at road.cc on the basis that these have already been carried out by specialist bodies, and the Hedkayse One conforms to the EN1078 European safety standard just like any other bike helmet you can buy in the UK and the European Economic Area (which is where Hedkayse will ship). If you want to know more about Hedkayse's philosophy on helmet safety, check out its 19-page technical review: Making Sense of Cycle Helmets.
Putting safety matters to one side, further benefits of Enkayse, according to Hedkayse, include that it's flexible enough to fit a variety of head shapes and that it can be made into a helmet that can be folded down for storage. Here's a video showing how.
That could be a benefit to cycle commuters or users of bike-share schemes who want to carry their helmet in a daytime work bag.
We measured the Hedkayse One at 21cm (wide) x 27cm (long) x 14cm (tall) in its normal state (the exact size will vary depending on how you have it set) and 14cm (wide) x 29cm (long) x 14cm (tall) when folded. The zipped bag you get for storage measures 20cm x 35cm x 14cm, although you can easily do without it if you're already carrying another bag for everything else you need for your day.
The folded size isn't tiny but what you might call the 'squishability' also comes into play. The Hedkayse is flexible enough that it can be persuaded to fit into a tight space in a backpack, for example, that would be much too small for a rigid helmet.
You need to bear in mind a few compromises, though. First, the Hedkayse One is pretty heavy. At 496g, it's twice the weight of some EPS helmets. Admittedly, it's sports-type helmets that tend to be lightest, but the Hedkayse One is also heavier than most commuter-style lids. No one wearing a helmet like this is going to be bothered about setting Strava KOMs but you can feel that difference in use.
Second, the fit isn't the most sophisticated ever. You put the Hedkayse One on your head, you adjust a thick hook-and-loop strap (like Velcro but not Velcro) at the rear to alter the circumference, you position the side buckles, and that's it. The helmet is one-size-fits-all – that's what the 'One' in the name refers to – and is officially suitable for heads from 49cm up to 58.5cm, but in reality it'll fit noggins much larger than that too.
As Hedkayse says, the expanded polyurethane conforms to the shape of your head, while the chinstrap is easy to adjust and has a clever quick release, but there's no internal fit system. You could argue that this isn't required on a helmet of this type, but I definitely felt that the Hedkayse One was perched on top of my head rather than encompassing my head.
Finally – and related to the above – the Hedkayse One was noticeably warmer on my head than many other bike helmets. You get four vents running lengthwise but there's a lot of helmet in direct contact with your head, preventing the free movement of air.
Fair enough, you might say, this certainly isn't a helmet that's designed for sports-type rides so what difference does ventilation make? Well, even fairly low-level rides from A to B can sometimes get sweaty and the Hedkayse can add to that feeling.
The Smith Network Helmet we reviewed on road.cc last year was £136, and that's a helmet with MIPS technology (the inclusion of which usually adds around £20). Bontrager's Charge WaveCel Commuter Helmet is £129.99.
The Hedkayse One is more expensive than either of these, although its impressive durability means it offers similar value.
The Hedkayse One isn't the lightest or the best ventilated helmet out there, but it's likely to be used for short (or at least shortish) rides around town where those things aren't top priority. The fact that it is compressible helps with stowage in a bag between rides, which will be an asset to many, and the materials used offer plenty of durability.
Innovative urban helmet that folds down for easy stowage in a bag between rides
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road.cc test report
Make and model: Hedkayse One helmet
Size tested: Single size fits head sizes 49cm - 58.5cm
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
It's a helmet for urban cycling (and skateboarding and rollerskating), particularly for those who need to carry a helmet between bike rides.
Hedkayse says, "The Hedkayse One is flexible, durable and smart. The first truly multi-impact cycle helmet of its kind. Designed and made in the UK from Hedkayse's own Enkayse material, you can be confident the Hedkayse One will take the bumps of everyday life and still protect when you need it most. Its patented folding design makes it ideal for the urban cyclist, commuter and bike-sharing user. Available in five colours.
"Whats in the box? Every Hedkayse One helmet comes in a helmet bag with spare comfort pads, and a "wrap strap" which can be used to hold it flat when folded."
Hedkayse lists these features:
Unique Enkayse multi-impact material
Conforms to the EN1078 Safety Standard
Patented folding design, reduces in width by 50%
Single size helmet fits head sizes 49cm - 58.5cm
Patented Quick-release Adjustable Ratchet Chin-strap (QARC) system
Designed and manufactured in the UK
Supplied with a branded "Wrap strap" for simple storage
Made in the UK
If you intend wearing glasses with this helmet, the arms need to go underneath the straps rather than over the top.
Tell us some more about the technical aspects of the product?
Hedkayse says this about its Enkayse material: "Of course Hedkayse One conforms to safety standards in Europe. But Hedkayse One is no fragile one-hit wonder. Because of Enkayse, Hedkayse One is able to pass safety tests after multiple impacts. That's pretty impressive considering the size of a single test impact alone is fairly fierce.
"Conventional helmets are made from polystyrene. In a large impact, polystyrene deforms to provide what's known as sacrificial protection. This is why you have to be careful not to drop your polystyrene helmet in everyday use, and it's why manufacturers recommend that you replace your helmet after a knock. Enkayse is designed to work differently.
"It manages the energy of impacts, so it can retain its integrity after more than one impact, large or small. Because Enkayse dissipates energy rather than deforming on impact, it also cushions small bumps.
"Polystyrene can't do this since forces which are too weak to deform it are transmitted through. Enkayse provides comfort in protecting from small bumps. This may also have long-term benefits as researchers believe the cumulative effect of small knocks contributes to brain disease over time.
"Because Enkayse shrugs off little bumps, it means that Hedkayse One is durable against the knocks and scrapes that come with everyday use. You can be sure that Headkayse One will stand up to the daily grind and get comfier to wear the more you wear it."
Hedkayse says this about its Tough and Flexible outer shell: "The vision of a one-size-fits-all, folding helmet wouldn't be possible without our flexible exoskeleton, exhaustively developed and refined.
"TAF (Tough and Flexible) is a specifically engineered rip-proof military grade Ballistic Nylon that forms the outer shell of the Hedkayse One. Lightweight. Strong. Easily washable.
"Its strength holds the helmet together, whilst providing the flexibility that allows the helmet to fold, and to adapt to all head types and sizes ranging from 49-58.5cm. Its low friction surface is designed to help minimise additional tugging forces from the road surface in the event of a crash."
Hedkayse says this about its X-Strap retention system: "Because Hedkayse One is so different from any other helmet, we knew that we'd need to create a fit system unlike any other.
"We designed the X-Strap retention system to be fully customisable, giving Hedkayse One the ability to fit multiple head sizes comfortably and securely.
"The X-Strap webbing and rear 'hook-and-loop' strap allow the helmet to fit heads from 49 - 58.5cm; the side buckles adjust to keep your ears from being squashed and our patented Quick-release Adjustable Ratchet Chin-strap (QARC) allows quick and easy removal no matter what you've got on your hands."
It's a smart design and robust with it.
It meets the EN1078 European safety standard, of course, and it compresses down in size when not in use. It is heavier and warmer than most rigid EPS helmets, though.
This is one of Hedkayse One's biggest draws. It can take a battering at the bottom of a bag and doesn't necessarily need replacing in the event of an impact. Hedkayse recommends replacement after five years.
You can get helmets that are half the weight although, to be fair, those are sports-type helmets. The Bontrager Charge WaveCel Commuter Helmet that we reviewed recently was 445g while the Smith Network Helmet was 303g.
The Enkayse material does conform to your head shape but the Hedkayse One is heavier than most, the fit system is basic and I didn't find the ventilation particularly effective. I didn't find it uncomfortable, but I didn't find it particularly comfortable either. That said, this is a helmet that's likely to be on your head for minutes rather than hours.
Tell us how the product performed overall when used for its designed purpose
The main purpose of a helmet is to protect your head, of course, and this one meets the same EN1078 standard as all others. Its other strength is that it can be compressed and stored in a bag without you needing to worry too much about damage.
Tell us what you particularly liked about the product
Durability and ability to be compressed and stowed in the bottom of a bag.
Tell us what you particularly disliked about the product
The fit didn't work especially well for me and I'd prefer more ventilation.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
The Smith Network Helmet we reviewed was £136, and that is a helmet with MIPS (the inclusion of which usually adds around £20). Bontrager's Charge WaveCel Commuter Helmet is £129.99. The Hedkayse One is more expensive than either, although its impressive durability means it offers similar value for money.
Did you enjoy using the product? Not especially.
Would you consider buying the product? I would if I frequently needed to store a helmet in a bag as a bike-share scheme user.
Would you recommend the product to a friend? As above.
Use this box to explain your overall score
This is a really tricky one to mark. The Hedkayse One offers very interesting tech but I feel that the fit needs to be improved in order for it to score higher than a 6.
About the tester
I usually ride: My best bike is:
I've been riding for: Over 20 years I ride: Most days I would class myself as: Expert
I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding
Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now pushing 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.