Climbing Helmet Construction

The number of climbers that wear helmets today is on the rise, and whether or not they wear a brain bucket largely depends on the type of climbing they do. Though many sports have a pretty consistent amount of helmet use as a piece of personal protection, it is still fairly spread out and nuanced in climbing. A good way to think about helmets when it comes to climbing and mountaineering is not so much as a piece of safety equipment but rather a piece of gear that helps manage risk, much like any piece of protection you would place in the rock.

How well a particular helmet helps us mitigate our climbing risk often comes down to its construction. The effectiveness of a climbing helmet depends on how it is made, the materials in play, and perhaps obviously, whether or not we even wear it. In this article we’ll break down the different helmet types, components, and design methods that brands use to make the gear that keeps our heads covered and what you should look for when comparing one helmet to another.

The Types of Helmets and Their Components

In the relatively short history of climbing helmets there have essentially been two main styles that climbers are familiar with– the hard, rugged plastic, heavy-duty brain bucket, and the molded, vented, lightweight foam sports car. There are hybrids of these two styles that we’ll get to in a bit but for now we’ll keep it as simple as hard shell and foam shell. Regardless of the type, most modern helmet construction can be summed up in 3 essential parts:

• The outer shell is the first line of defense against impacts and abrasion. This ‘shell’ forms the entire outer shape of the helmet.
• The foam liner adds shock absorption. Often a simple ‘puck’ of foam that sits on top of the head.
• The strap and suspension is webbing attached to the shell, liner, or both and dictates how the helmet attaches to your head.

Let’s start from the outside with the two main types of shells and work our way in.

The Hard Shell

The classic hard shell has been around essentially since the beginning of climbing helmets. When most folks think of a helmet, this is probably the one that comes to mind. A rugged, single piece construction outer shell is molded usually from ABS plastic. A thermoplastic like ABS(acrylonitrile butadiene styrene) is ideal for injection molding into very complex shapes which can maintain very rigid and durable forms (like a Lego brick) but also have a great deal of flexibility (like a common kitchen spatula).

A hardshell has the advantage of being very tough against both impacts and abrasion, but it is also the heaviest type of helmet and it often struggles with air flow.

The balance between vents and covered surface area is a tough one for manufacturers as the number of holes in a helmet increases airflow, but coverage of the head obviously goes down. Many helmet makers are now working in blends of ABS and Polycarbonate plastics in order to drastically lighten and improve a helmet’s ability to absorb repeated abuse, but they are still on average larger and much heavier than their foam counterparts. Rugged and able to stand up to multiple impacts and abrasions, this is the helmet that gear abusers and guiding services use.

One great advantage to a hard shell helmet is cost. Hardshell helmets have the highest durability and lowest cost. This is also why the Black Diamond Half Dome and Petzl Boreo/Borea helmets are some of the most ubiquitous helmets among climbers.

Since most brands who make helmets have at least one hard shell offering, and this will be the cheapest helmet they make, the competition is high and the price low. Sometimes lesser known brands will try to undercut the market to get their name out there or the price conversion to US dollars is wonky. For example Climbing Technology’s Galaxy helmet is currently one of the cheapest helmets available.

The Foam Shell

Although not a new thing per se, the past decade of improvements on molded foam helmets has expanded what is possible in the realms of style, low weight and protection.

The outer shell layer of foam helmets are typically made of expanded polystyrene (EPS, like styrofoam cups) with many newer designs incorporating expanded polypropylene (EPP, like your foam roller) which is known for being more elastic and better able to recover from small impacts. This foam layer is then coated in a very thin molded layer of polycarbonate (PC, like your Nalgene bottle) either covering all or part of the helmet.

The Camp Speed Comp is more typical of a foam helmet, with a thin outer layer covering the foam. The lightest helmets on the market either completely forego the outer shell poly layer as in the Grivel Duetto or in the case of the Black Diamond Vapor use materials such as carbon tubes and Kevlar.

Using a combination of this ultra thin ‘shell’ and the greater thickness of foam means these helmets can absorb a great amount of impact force while still being lightweight and able to have many openings for breathability. This makes them an ideal choice for hot and/or difficult climbing.

Foam helmets also tend to have a much more sporty visual appeal, something that many climbers say keeps them from wearing their bulkier ABS cousins. A helmet you won’t wear won’t protect your head. If you care about how you look in a helmet and it affects whether or not you wear one, then go for a foam shell helmet.

Foam helmets are generally more contoured to fit a specific head size/shape and can be more difficult to wear with a hat or if you have large hair or braids. This close fit has the advantage of greater protection lower on the head because the foam actually extends lower to absorb impacts from the rear and sides. An ABS shell doesn’t tend to have this side foam and generally doesn’t protect as well in side or rear impacts, but coincidentally the lack of foam gives more room around the whole head for a hat, head covering or large hairstyles, making them a more versatile fit.

One great disadvantage of a foam shell is its inability to handle repeated impacts. EPS and EPP are wonderful at crushing and absorbing force, but are less great at returning to their original shape, meaning most large impacts to foam helmets are often a cause to retire them completely. Foam helmets, especially those without poly shells, are also more prone to cracking in non-shock absorbing situations like when they are accidentally stepped on or stuffed into a bag full of heavy trad gear.

Bottom line: When every ounce counts, or you’re looking for the most stylish helmet, the foam helmet is often the choice. It excels for those hard sends with a lot of fall potential or where weight and high temps or visual aesthetic are of particular concern.

Foam/Shell Hybrids

Though it can be a hard thing to search, there are some helmets on the market that attempt to bridge Foam and Hard Shell tech into a best-of-both-worlds offering. Often found bridging the gap between lowest weight and highest price, hybrid helmets incorporate partial hard shells in strategic locations on the front and top of a typical EPP or EPS foam shell, allowing for maximum lightness and increased protection from rock and ice fall.

There are a handful of creative ways brands are designing these ultralight wonders. For example Mammut’s Wallrider uses ABS on top of EPP while the Sirocco from Petzl uses a combo of EPP with a puck of EPS and a poly cap, cutting weight and making it the lightest climbing helmet in the world currently. Always experimenting with new materials, Edelrid’s Salathe Lite employs a newer composite material called Curv over EPP for their cap, which Edelrid says is just as strong or stronger than ABS or PC at half the thickness.

Keep in mind that these hybrid foam / shell helmets also bring cons: a lack of durability due to the foam and a high cost due to the advanced manufacturing. The benefits are a lighter, more breathable helmet. They also tend to have greater head coverage than a typical hard or foam shell.

Liner and Suspension

Inside of every climbing helmet is a combination of 2 components: an adjustable nylon strap system woven through or around fitted foam. While every manufacturer has their own flavor of this suspension, varying from simple webbing with buckles to ratcheting slider systems and twist wheels, the thing that they all have in common is that they work in conjunction to connect the shell of the helmet to your head and keep it there.

In a hard shell, an EPS or EPP liner is necessary to give the suspension somewhere to attach, allowing the shell to sort of ‘float’ about the head and do the bulk of the impact absorption. This ‘liner cap’ also provides additional crush protection if the shell fails due to a sharp impact from above, and is the main part of the helmet you feel against your head once it is attached.

One pro of the hard shell helmet is its adjustability to fit many sizes of heads both comfortably and correctly due to the foam liner being mostly on top of the head. This allows for a greater range of movement and tightening of the strap system around hair, hats, and head coverings. This is why many hard shell helmets are one size fits all, whereas many foam helmets come in two sizes.

Some straps adjust around the back of the skull with simple buckles, while others use more complex ratcheting clips or dials, allowing them to be adjusted more easily on the fly. If you are the only person to use your helmet, this is usually no big deal, but if you want to go with or without a hat or are sharing a helmet with others, the ease of adjustability can really be a big factor on whether or not you will choose to wear it.

In foam and hybrid shells, there is usually no liner and the suspension anchors straight through the foam shell of the helmet itself. This means that wearing a correctly sized foam or hybrid helmet is considerably more important, as the fit relies on the entire size and shape of the foam, rather than the internal cap you would find on a hard shell.

Because all helmets are made from a mold, it isn’t guaranteed you will find them in multiple sizes. This is because a manufacturer must pay to create and maintain essentially two ‘different products’ worth of molds when compared to a helmet that comes in one size, so helmets that come in one size might not extend to the larger end of the spectrum to accommodate larger heads. This ‘one size fits all’ approach can be good or bad depending on your head and hair size. For example, a smaller head will have more room for things like hats or larger hair styles. That being said, it is more likely you will find a foam or hybrid style helmet that comes in 2 sizes than a hard shell.

When choosing a helmet, the type of materials and construction plays just as big a role as the type of climbing you plan to do. The difference between staying light, fast, and cool versus protecting against rockfall or ledge impacts is very much driven by the helmet you choose to wear (or not to wear). Some climbers may find themselves owning multiple helmets to optimize performance in each situation, while others will compromise their occasional sweaty head for a rugged shell they can toss around or go ultralight and take extra care when transporting this foam racecars.

If you’re still on the fence about which direction your needs may take you, we have a comparison tool built right into WeighMyRack.com where you can filter and compare every helmet currently available based on sizes, features, brands, prices, and more. After you lay the sports car nogginbox out next to the trusty suv brainbucket and see all of their features side by side, you might find you want both or maybe even discover something you never knew you would need. Only one way to find out.