Made for the Descent: Leatt MTB 4.0 AllMtn Helmet Review

Leatt MTB 4.0 AllMtn Helmet
Photos: Matt Miller unless otherwise noted

A mountain bike helmet is a mountain bike helmet is a mountain bike helmet. But not always. Some helmets are clearly intended for a certain style of riding, like the Leatt MTB 4.0 AllMtn V22 helmet we’ve been testing.

What makes the Leatt AllMtn 4.0 special? The hefty half-shell is new this year to Leatt’s line and it has some great features that suit its all-mountain/enduro intentions.

Leatt MTB 4.0 AllMtn helmet specs

The helmet has a Polymer shell, a sunglasses dock port, a magnetic Fidlock buckle, an adjustable visor, anti-odor padding, 18 vents for ventilation, and Leatt’s patented 360° Turbine rotational force reduction system.

Leatt MTB 4.0 AllMtn helmet inside
Leatt’s Turbine discs in blue

The Turbine system features small discs made of Armourgel under the helmet. Armourgel absorbs linear energy while the discs move around laterally to mitigate rotational forces from a crash.

The Leatt AllMtn 4.0 V22 helmet weighs 477g for our size medium and costs $189. It comes in this jet grey/rust color and also an ivy green colorway.

Ride impressions

Photo: Hannah Morvay

The first thing that strikes me on the Leatt is its size. While it may not be much larger than other all-mountain helmets, it has a seemingly larger profile than competitors. The lower half of the helmet provides good coverage around the temples, forehead, and the back of the skull. Above the crown is where the bulk seems to be.

The AllMtn 4.0 has a rather large visor that creates a solid plane from the crown of the head to above and ahead of the nose which stands out and gives the helmet a larger appearance. It’s not the lightest helmet either at 477g for a size medium.

To get all of the gripes out of the way early on, this helmet isn’t the most ventilated either. There is noticeable airflow coming through while moving, but it is not as much as say the Giro Manifest or Fox Speedframe, and the Leatt helmet warms up quickly during stops for water or air.

Should all of this be surprising? That an all-mountain/enduro half-shell helmet is not as breathable, slim, or light as other mountain bike helmets? Probably not.

The Leatt does stand out with a few of its features though. I’ve noticed that most of the time if I can ditch the hard plastic MIPS liner for another piece of concussion tech, it’s usually more comfortable. The Leatt Turbine discs reduce the necessary layers inside the helmet to keep riders safe and that increases comfort. So does the thick padding inside, but that may also make it a little warmer. Aside from the ventilation, it’s a pretty comfortable helmet.

Leatt made the AllMtn 4.0 helmet with ample room for specs. Above the brow there is a lot of space for goggle stowage, and above the temples are rubber slotted pieces for sunglasses.

Closing thoughts on the Leatt MTB 4.0 AllMtn

Leatt’s AllMtn 4.0 V22 helmet is like most any other bike product on the market: made for a certain type of riding. With the thick padding, big visor, aggressive look, and room for goggles, it’s easy to tell that Leatt built this one with descending in mind. If you’re looking for a descent-oriented helmet, the AllMtn 4.0 is a great option.

  • Price: $189USD
  • Available at Amazon.

Check out our mountain bike helmet buyers guide and our picks for the best mountain bike helmets.

Party laps

  • Comfortable
  • Magnetic Fidlock buckle
  • Room for goggles, glasses

Pros and cons of the Leatt MTB 4.0 AllMtn V22 helmet

Dirt naps

  • Warm
  • Large(ish) profile