Leatt MTB 4.0 Enduro V21 review

Is Leatt’s convertible enduro helmet the best of both worlds for high-risk trail riders and racers?

Leatt MTB 4.0 Enduro V21
(Image: © Guy Kesteven)

Bike Perfect Verdict

Distinctively angular and airy convertible helmet with full DH safety and some neat fit and feature details


  • +

    Full DH certified

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    Decent ventilation

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    Relatively light

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    Solid chinguard lock

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    Brain injury protection

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    Fidlock buckle

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    Optics friendly

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    Four colors


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    Awkward chinguard release

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    Standard full face is cheaper

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    No GoPro mount

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South African brand Leatt’s new removable chin guard enduro helmet still meets ASTM DH certification standards despite being a part-time full-face helmet. The MTB 4.0 helmet includes a load of smart features too including their own brain-saving 360º Turbine inserts, plus it’s relatively light too. The demanding nature of modern enduro tracks has meant the convertible helmet market has become hotly contested, is Leatt's offering enough to make it one of the best enduro helmets available.

Construction and performance

The angular design of the MTB 4.0 Enduro V21 is an evolution of Leatt's equally distinctively styled DBX 4.0 fixed full-face helmet. The obvious difference are the two magnesium levers at the back of the separate chin piece which rotate diamond key plates on the inside to lock the chin into place. Metal hooks at the top edge give the second locking point and once they’re all engaged the chin is totally locked in place without any rattle or creaking. Chunky press-fit jaw pads add stability and protection but there’s no padding around your ears so hearing and airflow are uninterrupted. Big vents on the side of the chin add cooling and you’ve also got the option of popping out the geodesic plate in the front of the mouthpiece to boost direct airflow.

The upper helmet is essentially the same as the MTB 4.0 AllMtn V21, just with the extra chin piece anchor points. You still get a full hardshell wrap for cosmetic protection and the black and white material inside marks the different EPS (Expanded Polystyrene) and EPP (Expanded Polypropylene) construction elements.

The 13 vents are mostly grouped at the rear of the helmet but two large brow vents under the distinctive flush fit peak feed into internal channels and a high exhaust vent. Limited, shallow pads in the washable liner mean the other exhaust ports suck air through easily too. That also means the rubber spoked wheels of the ‘360º Turbine Technology’ contact your head directly managing the ‘slip plane’ deceleration in a hard crash and potentially reducing rotational stress on the brain by 40 per cent and impact force by 30 per cent in a crash. The adjustable peak breaks away in a crash too and with the chin guard on the helmet meets AS/NZS 2063:2008, ASTM F1952–10, EN1078 and CPSC 1203 standards.

Three shell sizes and a dial tightened cradle with three height settings make for a comfortable and secure fit with or without the chin guard attached. The FidLock magnetic buckle on the straps is blissfully easy to use, but there are no ‘Y’ sliders so smaller heads might find the strap junction sits right on their jawline. The peak sits just over the helmet brow in the lower position with further mid and high positions giving space for glasses or goggles underneath. Finned rubber ‘dock’ segments behind the peak flanks add grip for glasses frames too. Leatt doesn’t make their own specific GoPro/helmet light mount to plug into the lid though.


The MTB 4.0 Enduro V21 was a solid and secure fit from the start, with no creak or rattle to suggest you aren’t wearing a fixed full-face helmet. Protection is excellent while staying reasonable light too. Ventilation and acoustics are good and the buckle and glasses features are really nice touches. The extensive feature list makes the price high but not unreasonable for the ‘two excellent lids in one’ performance you’re getting. The MTB 3.0 Enduro V21 delivers a lot of the same features but a different chin locking mechanism for £80 less if you’re cost-conscious anyway.

Tech specs: Leatt MTB 4.0 Helmet Enduro

  • Price: $299.00 / £279.99 
  • Weight: 850g (medium)
  • Colors: Black, Sand, Chilli, Cactus (tested)
  • Safety: Leatt  360º Turbine - AS/NZS 2063:2008, ASTM F1952–10, EN1078 and CPSC 1203 
  • Sizes: S, M, L
Guy Kesteven

Guy has been working on Bike Perfect since launch in 2019. He started writing and testing for bike mags in 1996. Since then he’s written several million words about several thousand test bikes and a ridiculous amount of riding gear. To make sure he rarely sleeps and to fund his custom tandem habit, he’s also penned a handful of bike-related books and talks to a GoPro for YouTube, too.

Current rides: Cervelo ZFS-5, Specialized Chisel, custom Nicolai enduro tandem, Landescape/Swallow custom gravel tandem

Height: 180cm

Weight: 69kg