An open-face helmet gives you the same skull protection as a full-face helmet and nothing at all across the chin, jaw and face. That is not a criticism from a rival camp — it is how MotoCAP, the Australian government-backed gear rating programme, describes the category in its own guidance. If you ride in an open face, you are accepting facial injury as a possible outcome in exchange for airflow, peripheral vision, easy communication and a look you like. Those are real benefits. The honest version of this article is that they are benefits you are buying with your jaw, and there are ways to reduce the price without giving them up entirely.
What the chin bar is doing on the helmets that have one
The clearest evidence is not a statistic, it is the hardware afterwards. A full-face helmet that has slid down a road comes back with the chin bar ground flat on one side, gouged through the paint and into the shell. That damage is the record of a surface that was in contact with tarmac while a face was behind it.
An open-face helmet in the same slide puts your cheekbone, jaw and teeth on that surface instead. It also leaves your face exposed to the second common event, which is contact with something that is not the road: a kerb edge, a barrier post, the corner of a car. MotoCAP's test description is explicit that their impact programme uses a simulated kerb anvil precisely because "a hard metal edge such as a kerb, roadside barrier or corner of a vehicle" is a realistic thing to hit, and they use a higher impact speed on that anvil than UN Regulation 22 does. A chin bar is the only part of a helmet positioned to take that kind of edge contact on behalf of your face.
Half helmets are a different and worse proposition
"Open face" gets used loosely for two quite different designs. A three-quarter or jet helmet has a shell that wraps down over the ears and around the back of the skull, and only the face is open. A half helmet — the shallow shell that sits on top of the head like a cap — leaves the temples and the area around and below the ears uncovered.
That matters because of what a helmet is required to cover. MotoCAP states the requirement plainly: a helmet must "cover the frontal and temporal areas of the head". The temporal bone is one of the thinner parts of the skull and sits over a major artery. A shell that stops above the ear is not covering it.
Certification is where this gets sharp. Plenty of shallow shells are sold as fashion accessories with no approval at all, sometimes with a sticker that resembles a certification mark. In the United States the requirements behind a genuine DOT label are set out in 49 CFR 571.218, Federal Motor Vehicle Safety Standard No. 218, which specifies impact attenuation, penetration resistance and retention system strength. A helmet wearing the sticker without having passed the tests is a decoration. In the UK, the legal list is BS 6658:1985 with a BSI Kitemark, UN Regulation 22.05, UN Regulation 22.06, or a recognised European equivalent — nothing else is road legal, however retro it looks. The differences between the schemes are unpacked in the guide to motorcycle helmet safety standards.
| Design | Skull coverage | Face and chin | Typical honest use case |
|---|---|---|---|
| Half helmet | Crown only; temples and ears exposed | None | Very low speed, and only if genuinely certified |
| Three-quarter or jet, no visor | Full, including temples and rear | None; eyes need separate approved protection | Town riding, warm climates, classic machines |
| Three-quarter with a full visor | Full | Eyes and some wind protection; chin still open | The best version of the open-face compromise |
| Flip-up, bar closed | Full | Full while latched | Riders who want an open face at lights and a chin bar in motion |
| Full face | Full | Full | The reference case for everything else |
Eye protection is a separate legal item
An open-face helmet leaves the eye protection problem to you, and sunglasses do not solve it. The UK rules state that a visor or goggles worn on the road must meet a British Standard with a Kitemark, UN Regulation 22.05 or 22.06, or a recognised equivalent. Ordinary sunglasses carry none of those approvals and are not built to stop a stone. MotoCAP makes the practical version of the same point: helmets without a visor let insects, dust and wind reach the eyes, which causes discomfort or injury unless goggles are worn.
The everyday failure is mundane and disabling. A wasp at 80 km/h, or a stone off a truck tyre, hits an unprotected eye and both eyes close reflexively. There is no version of that which ends well on a moving motorcycle. If you are going to ride open face, ride it with an approved visor or approved goggles fitted, not with eyewear chosen for style.
Retention, age and the second-hand vintage trap
Retro-styled helmets often come with retro-styled straps: thin webbing, a snap fastener, or a buckle designed to look like something from 1968. Test the helmet the way you would test any other. With the strap fastened, tilt your head forward and have someone try to roll the helmet off the back of your head by lifting at the rear lower edge. If it comes off in a shop it will come off in a crash, and a shallow shell with a light strap is the easiest of all helmets to displace.
Genuine vintage helmets are worse. MotoCAP's guidance gives a working life of around five years, or three with regular use, and warns that helmets should be kept away from harsh chemicals, petroleum-based solvents, prolonged sunlight and excessive heat because those degrade the materials with no visible sign. A helmet from the 1970s has had fifty years of all of it. Their advice against buying second hand at all — because there may be little external evidence that a helmet has taken a serious impact — applies with particular force to something bought for its patina. The full reasoning is in the guides to when to replace a helmet and the risks of buying a used helmet.
Wearing an old open-face shell as a display piece is fine. Wearing it on the road is choosing decoration over the only equipment standing between your skull and the ground.
How to keep most of what you like and lose less of your face
Four practical moves, in order of how much they give back. Choose a three-quarter shell rather than a half shell, so the temples and the back of the head are covered. Fit a full-length approved visor rather than a short peak visor, which restores weather and debris protection and takes the eye protection question off the table. Buy a shell that is certified to a current standard even if it is styled to look forty years old, because plenty of manufacturers now sell exactly that. And treat the open face as a category for the riding it suits — town speeds, warm weather, short trips — rather than as an all-conditions helmet.
The alternative worth considering honestly is a flip-up. It gives you the open-face experience at lights, in queues and while talking to people, and a homologated chin bar the rest of the time. It costs weight and adds a latch you have to remember, and for a lot of riders that is a better trade than the one an open face asks for. The types are compared in the guide to motorcycle helmet types, and the daily-use considerations in the guide to choosing a commuter helmet.
One thing an open face genuinely does better: you hear the world. Traffic, your engine, a siren behind you. If that awareness is why you ride one, keep it and add a record of what happened rather than relying on memory — a front and rear camera system mounted on the bike does not interfere with the helmet at all.
Frequently asked questions
How much less protective is an open-face helmet?
For the skull, not less at all — the shell coverage over the cranium is comparable. For the face, jaw and chin the protection is zero, and those are the areas a chin bar exists to cover. It is a specific loss rather than a general one.
Are half helmets legal?
Only if the specific helmet holds an approval recognised where you ride. Many shallow shells sold for the look carry no valid certification. Check for a genuine UN Regulation 22 label, a BSI Kitemark against BS 6658, or a real DOT certification, and be suspicious of stickers that merely resemble one.
Can I wear sunglasses instead of a visor with an open-face helmet?
Not as your eye protection. Road-legal eye protection must meet an approved standard, and sunglasses do not. Fit an approved visor or goggles, and wear the sunglasses behind them if you want the tint.
Is a vintage open-face helmet safe to ride in?
No. Helmet materials degrade with age, heat and ultraviolet exposure with little visible evidence, and guidance puts the working life at around five years, or three with regular use. Buy a modern helmet styled to look vintage instead.
What about a three-quarter helmet with a full visor?
That is the strongest version of the open-face compromise. You get full skull and temple coverage, proper eye and weather protection, and the airflow and hearing that made you want an open face. The chin is still exposed, and no visor changes that.
