Summary: Folding bicycle helmets are easier to carry off the bike and could be useful for shared bicycle system users. There are some decent ones on the market, including some that meet US standards.
Folding a helmet can make it easier to carry, so users of folding bicycles have always found them appealing. Users of shared bicycle systems would like a collapsible helmet they could tuck into a purse or briefcase and pull out when they use one of the shared bikes.
Although a helmet may fold, if it uses conventional materials it still requires the same volume of impact foam. To manage the energy of an impact, the foam must be thick enough to give the head enough distance to stop in a controlled deceleration. So the helmet materials can fold, but the volume of material itself will be the same, limiting the compactness. In addition, the helmet has to maintain its structural integrity in an impact, requiring engineering skill and probably more expensive materials to construct. Designs that escape that rule may be coming, but are not on the market yet.
The first folding helmet we know of that met the US CPSC standard was the Motorika Snapit, introduced in 1997. It was a clamshell design with one half folding inside the other. We did not like the external ridge left from back to front when it was unfolded in use, and the 16 oz. (454 grams) weight discouraged some buyers. It disappeared from the market soon after the turn of the century, but others have emerged:
Biologic has two sides that fold into the center. It does not meet the CPSC standard, so it is not available in the US market, but it meets the CEN standard and is sold in Europe. This YouTube clip from the 2012 Eurobike show shows it in action, and there is more on it here. There are variations including the Foldable Crit model. Carrera says they fit well because of the folding construction. We don't like the gaps between the strips on the front edge, leaving corners that might do more damage to your face in a crash than a continuous edge would. Initially designed only to the European EN 1078 standard, Carrera says they now have CPSC models as well. Online prices vary widely.
The rings give the helmet an unusual round profile. Unfortunately the Closca has a cloth cover rather than plastic. It retails on their web site for €62.
For 2019 Closca has introduced their new Loop model, known in the US as The Stack or The 174 Hudson Stack. The shape is a little different from the original Closca, with a forward-swept lower ring. But the concept is the same, with telescoping rings that Closca says reduce the helmet's volume by 45%. And fully extended the helmet is round and smooth. Certified to the US CPSC standard and to EN1072. Cost is €70 in Europe and $80 in the US through Priority Bicycles.
Fend has developed a folding helmet with ribs that fold in from the sides to stow the helmet. Their site says it is CPSC and EN 1078 certified. Comes in white, black and "NY Yellow." Retail on their site is $120 with free shipping.
It is advertised as made of "cardstock." There is nothing on the WeshineOnline site about meeting any standard. Weshine Online is a Chinese company, but to sell in the US the helmet has to meet the CPSC standard. The price is lower on Amazon at $30, and $36 on the Weshine Online site, but Weshine includes shipping.
OthersHeadKayse has run an Indiegogo campaign to develop a new soft helmet that folds, promised in early 2017. The design is interesting, with no standard EPS foam but a flexible material they call "Enkayse." It is a multi-impact material and the manufacturer says it outperforms EPS in lesser impacts. They say the helmet flattens to less than 2" (5cm). Designed only for the European EN1078 standard. See the web page for more. We subscribed to the campaign and are waiting for our sample.
Park & Diamond has developed a folding (or rollup) design and is promoting it with an Indiegogo campaign. The design "Looks and feels like a baseball cap," but has a strap and is designed to meet the CPSC standard. Weighs 8 oz. Estimated delivery was February 2019, but we have not received ours yet.
Put A LID on It has been developing a low cost folding helmet designed for shared bicycle programs, particularly the London system. In mid-2016 their site said they will launch the crowdfunding effort soon.
Spitfire Industry is developing a new Eco Helmet model made of recyclable paper in a radial honeycomb pattern. This will be an exciting new model if it can meet standards. It folds flat and is said to be very inexpensive to produce. They are intended to be readily available for shared bike system users.
Although the web site says "Crash Tested. Absorbs blows like traditional styrofoam." and "EcoHelmet absorbs blows from any direction as effectively as traditional polystyrene," a media report says it is not yet certified to CPSC as of August 2016. The testing shown in the company's video does not even approximate the CPSC impact test protocol, and CPSC requires testing after at submersion in water for up to 24 hours, a real challenge for paper waterproofing. EcoHelmet plans to launch early in 2017. We hope they find the right materials to make the design work. (June, 2017: Weshine is marketing what appears to be the same design--see above)
Bottom lineFolded or not, a helmet is another item for a pedestrian to carry unless planning in advance to use a borrowed or shared rental bicycle. That may not be a problem for backpack users, but those with purses or briefcases can't tuck a non-folding helmet inside them. We are glad to see models in the market that meet the US standard, and hope for more.
This page was revised or reformatted on: August 20, 2019.