Winter Kit Special: 20% Off A Top & Bottom | Shop Now
This carousel displays a list of buttons that updates the main product image when a button is clicked
  • Options
  • Detail Images

LeattMTB 4.0 AllMtn Helmet

Sale $151.99 - $189.99

Item # LBRI063

Select options
  • Cancel
  • Select options
  • Black, L ($189.99)
  • Black, M ($189.99)
  • Black, S ($189.99)
  • Cactus, L ($151.99)
  • Cactus, M ($151.99)
  • Chilli, L ($189.99)
  • Chilli, M ($189.99)
  • Chilli, S ($189.99)
  • Rust, L ($189.99)
  • Rust, M ($189.99)
  • Sand, L ($151.99)
Add Protect+ Powered by Extend™
  • 100% Guaranteed Returns
  • Free Shipping on orders over $50

Item # LBRI063

Why We Like The MTB 4.0 AllMtn Helmet

Brush up on your history of Leatt, and you'll discover a rich past based upon the creation of safer, smarter equipment for those that ride off-road. The California-based brand's two decades of experience has provided us with reliable gear from body armor to neck braces, and the MTB 4.0 AllMtn Helmet is their latest launch to offer superior protection at an affordable price. Its rugged frame is built from a lightweight polymer compound to reduce neck fatigue as you grind up the mountain, and EPS foam handles higher speed impacts no matter where the trail takes you. We especially like Leatt's 360-degree Turbine Technology, which dramatically reduces harmful rotational and low-G impact forces.

  • Rugged helmet tackles trail rides and enduro
  • 360° Turbines guard against low-speed and rotational impacts
  • Polymer shell pairs with EPS foam to absorb greater impacts
  • Dri-Lex liner wicks moisture to promote breathability
  • Fidlock magnetic buckle for easy entry and exit

Tech Specs
Shell Materialpolymer compound
Ventilation22 vents
Fit Adjustmentretention dial
Full Faceyes
CertificationsAS/NZS 2063:2008, ASTM F1952–10, EN1078, CPSC 1203
Manufacturer Warrantylimited


Head Circumference

20.8 - 21.25in

(53 - 54cm)

21.6 - 22in

(55 - 56cm)

22.5 - 22.8in

(57 - 58cm)

23.3 - 23.7in

(59 - 60cm)

24 - 24.5in

(61 - 62cm)

24.8 - 25.2in

(63 - 64cm)

How to Measure:
Measure the circumference of your head with a tape measure. Place the tape measure slightly above the ear and bring it across the mid forehead completely circling the head about 1 inch above the eyebrows. Take several measurements to make sure you have the largest size. If you do not have a tape measure, use a string and measure it against a ruler.

What do you think about this product?


>Rating: 1

Extremely Disappointing

I've used it several times
Runs large
Size Bought
6` 5"
225 lbs

Upgraded from a 3.0 to this and couldn't be more disappointed. The retention dial broke and fell apart after just a handful of rides rendering the helmet completely useless. I purchased the helmet early in the year and didn't get to ride much due to the very wet spring in Colorado this year. Unfortunately, that means that the helmet was past the 30 day return window for Backcountry when it failed. Hopefully Backcountry will do the right thing and resolve this equipment failure.

Contact Leatt. They’ll likely warranty it and will directly contact Backcountry if needed.

>Rating: 4

Serious Helmet

I returned this product before using it
True to size
Size Bought
5` 10"
165 lbs

Bought the 3.0 and this one (4.0). The quality and fit seemed very good for this range of MTB helmets. Adjustment was easy and fit was very good. Returning because it is a bit heavier than the 3.0 and was more protection than I probably need doing slower, technical riding. These helmets (Leatt) appear to fit more oval-shaped domes. Wasn't overly impressed by the eyeware on-board storage but I also didn't try very hard to make my Smith Longfins attach easily.

>Rating: 2

Look out Dark Helmet!

I returned this product before using it
Runs large
Size Bought
6` 1"
215 lbs

This thing is massive! Very nice looking, but way too huge! Sticks off the head more than any helmet I have owned. I was super disappointed in how grande this helmet fit because of how awesome it looks. I wanted to keep it, but I knew my riding buddies would ridicule me with endless Space Balls jokes... It's that big!


This is a full face?

Hey there, this is not a full face helmet.