Convertible helmets are nothing new, with the original Giro Switchblade being introduced over 30 years ago. Since then, the likes of Met and Bell, have joined the fray, introducing open-face lids with bolt-on chin bars since that let you maximise airflow on trail rides, and double down on protection in the bike park.  And both brands have found spots on our rundown of the best convertible full-face helmets. But until now, no brand has come up with a 3-in-1 model. Leatt’s MTB Helmet 3.0 changes all that with the option to add extended ear protection, or a chin bar, to the basic open face design.

With the ear pieces installed, the Leatt MTB Helmet 3.0 is stable, comfortable, and good-looking

Design and specifications

Starting with the bare bones, in open face mode Leatt’s MTB Helmet 3.0 uses a typical enduro helmet shape, with extended coverage at the back and subtle shaping to follow the top of the ears. The peak protrudes quite a long way forward, and in the lowest of its three positions sits fairly prominently in your field of vision when riding. Tip it up one notch and it disappears, but the visor still looks a little duck-billed and out of proportion when set up as a halfshell.

Leatt’s polymer shell is fully in-moulded with the EPS foam and comprehensively bottom-wrapped around the edges to help protect it from knocks. Inside is Leatt’s in-house 360º Turbine rotational protection technology. These rubbery, blue, fan-shaped doughnuts are designed to do a similar job to MIPS, by moving independently of the shell in a crash, reducing the acceleration forces on your brain by up to 40% Leatt claims. We couldn’t actually feel them when wearing the helmet – it’s only when forced against your scalp when it hits an object that they come into play.

The blue fans are Leatt’s 360º Turbine technology, designed to reduce rotational acceleration and associated brain injuries

To achieve optimal fit and comfort, the Leatt MTB 3.0 is available in three shell sizes, and by using the internal retention band to tune the fit, each helmet will accommodate 4cm of circumference variation. The micro-adjuster dial itself is fairly large, but the detents are not particularly distinct, and with the retention band in the highest position (of three) it’s tricky to access.

Leatt boasts that there are 20 openings in the shell, but that’s slightly misleading as only 13 of those are in the main helmet, another two if you add the ear extensions (the latest Fox Dropframe has 18 in total). Deep channels help direct airflow over the top of your head, and you also get moisture-wicking, breathable, anti-odour pads, with two thicknesses in the box – 8mm and 10mm.

Converting the helmet between modes is simple. Simply locate the bent metal tabs found on the ear defenders and chinbar into the recesses at the side of the main helmet, press the buttons and locate the twist-locks. Removing them is slightly trickier, as you have to press the buttons while pulling the accessory, but we soon got the knack of it.

One final detail that we approve of is the Fidlock magnetic buckle. It’s so easy to fasten, you can actually close it or release it with one hand.

With the chinbar installed the Leatt MTB Helmet 3.0 is hard to get on and even harder to take off

Performance

As an open-face helmet, the Leatt MTB 3.0 is comfortable and stable. We found we had to put the retention device in the lowest position to sit under the occipital lobe, but once cinched up it didn’t move excessively, despite being heavier than average at 462g. There are open-face helmets that are more stable, such as the Troy Lee Designs A3, but to a certain extent it depends on the shape of your head. With the chinstrap done up it was stable with no obvious pressure points. It’s definitely not the best ventilated helmet, but we didn’t find it too stuffy on summer rides.

Attach the ear covers – you’ll need to take the helmet off to do this – and the MTB 3.0 immediately seems like a more serious proposition. It’s noticeably more stable, and we didn’t need to tighten up the retention device to stop any movement. There is some added pressure from the pads to the ear lobes, but it’s not uncomfortable, and there’s no reduction in hearing. However, putting the helmet on and taking it off is much more difficult.

Leatt doesn’t have the most ventilation, but for most climates it works fine

Mounting the chinbar takes a bit of force, but increases protection to DH-certified levels. With the tabs in place, you have to spread the opening and stretch it into the recesses.

Once fitted, getting your head in is a bit of a squeeze, even with the retention device fully open. We’ve tested some convertible helmets that have been harder to get on, but it’s definitely more difficult than something like the highly rcommended full-face Specialized Gambit. It also felt like it was going to rip our ears off when removing it with the chinbar in place. So we ended up removing the chinbar to take the helmet off, which would be a total faff if you had to do it at the bottom of every run on an uplift day or an alpine holiday. It’s certainly not unique in that respect, but it does mean that if you’re looking mainly for a full-face that will be used occasionally as an open-face, you may be better off going for a dedicated full-face design.

Leatt has provided space to park your goggles under the peak, and vents to hold your sunglasses if you want to take them off on a climb. We didn’t find this particularly comfortable however, as the arms wedged against our head inside the helmet. And on the subject of glasses, the top of the frame would rattle constantly against the underside of the helmet on every descent, which was incredibly distracting.