Leatt Velocity 4.0 MTB X-Flow Goggles review – excellent venting and airflow

Premium performance eye protection that will appeal to the enduro and DH crowd and may even convert some google skeptics

Leatt Velocity 4.0 MTB X-Flow Goggles sitting on mossy rock with a Bike Perfect recommends logo
(Image: © James Blackwell)

Bike Perfect Verdict

With outstanding ventilation, a unique frame design and premium performing lenses, the Velocity MTB X-flow Goggles should appeal to the masses. The fit is more subjective though and you’ll need to consider how and where you ride before dropping your dollars.


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    Unique design with a cut-away lower frame

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    Amazing airflow and anti-fogging

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    Tough lenses with amazing clarity

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    Unobscured wide peripheral field of view

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    Look cool


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    Slight pressure point at nose piece

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    May suffer from mud ingress

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    Strap is pretty tight

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South African brand Leatt aren’t scared of a little innovation, its new Velocity 4.0 MTB X-Flow boasts unbelievable levels of ventilation and breathability and a unique frame design. Paired with its Bulletproof 170-degree WideVision RideViz MTB Lens and some cracking understated styling, they will appeal to enduro, DH riders, and anyone who likes a bit of bike park action. I slipped on the full-face helmet to see how they measure up to the best mountain bike googles out there.

Close up of large top vents of the Leatt Velocity 4.0 MTB X-Flow Goggles

The open design at the top of the frame offers up ridiculous amount of airflow (Image credit: James Blackwell)

Design and specifications

The X-flow frame is all about airflow. The fully open upper and lower frame has no mesh covering whatsoever, it’s a bold and unique design for optimised airflow and anti-fogging and features dual-layer foam for comfort. The frame also features an OTG – over-the-glasses fit.

Even the strap, which is made from large size mesh, allows air to pass through it – perfect if your strap covers critical vents on your helmet – and the strap gets three lines of rubber silicone to keep it in place.

shot showing the open vents on the Leatt Velocity 4.0 MTB X-Flow Goggles

The open frame design of the Leatt Velocity 4.0 MTB X-Flow Goggles is all about airflow but it did create a slight pressure point around my nose (Image credit: James Blackwell)

The lenses offer up a wide 170 degree field of vision and use Leatt’s Bulletproof RideViz Lens technology. This features an anti-fog coating, scratch resistance and are tested to US military ballistic standard (MIL-DTL-43511D) – just google it and you’ll see that they are really tough!

Close up of the open frame design on the Leatt Velocity 4.0 MTB X-Flow Goggles

The goggles have a unique design that may convert skeptics with its glasses style fit (Image credit: James Blackwell)


The first thing I noticed was how tight the strap was, trying it with a few different full-face medium sized helmets I had to extend the buckle to it’s full length to allow for a comfortable fit. It started to give a bit after a few rides and some gentle persuasion, but I still had to wear it almost to the strap's full extension. This will be more of an issue for bigger helmet sizes, so it would be worth trying a pair before you commit to buy.

Although the frame has truly huge vents and an open lower frame, it’s still really stiff which was a surprise. This stiffness didn’t affect comfort though and they fitted well with the ABUS Airdrop MIPS, Met Parachute and absolutely seamlessly with the Leatt Enduro 3.0 helmet which makes sense given its enduro DNA. The open frame design of the X-flow has an almost sunglasses feel, so may well appeal to the anti-goggles wearers out there. 

detail shot showing the mesh strap on the Leatt Velocity 4.0 MTB X-Flow Goggles

Even the strap is designed to allow airflow should it cover any critical air vents to the side or rear of the helmet (Image credit: James Blackwell)

Airflow is ridiculous though. I overheat quickly and tried my hardest to get them to fog – I couldn’t. I kept them on run after run and they performed really well. Even standing still post run, I didn’t feel the need to remove them as air circulation is excellent. The perforated strap helped to allow critical vents on the side and rear of my helmet that get covered up by a strap to breathe too.  

The lens clarity is fantastic and with the wide field of vision paired with the open lower frame provided excellent peripheral vision.

close up of the Leatt Velocity 4.0 MTB X-Flow Goggles' lens

The nose piece created a slight pressure point on my nose (Image credit: James Blackwell)

Unlike traditional frame designs where the foam completely surrounds the frame for even pressure distribution, the X-flow did create a slight pressure point over my nose. I do have a small nose and it’s pretty wonky if I’m honest, but the lower open section does seem to create this pressure point. I’m hoping that with more use the strap will slacken a bit to negate this.

Although I was mainly riding in warm weather on solid trails, I’d say there is a definite risk of trail debris from riding loose or really muddy trails getting thrown up and down into the frame. It’s a real consideration, but I didn’t experience any problems.

The Leatt Velocity 4.0 MTB X-Flow Goggles fitted on Leatt Enduro helmet

Fit from the is seamless with the Leatt MTB Enduro 3.0 Helmet. It's also great with the other helmets I tried too (Image credit: James Blackwell)


In the fight for supremacy against big hitters from likes of Oakley, Smith and Fox, the Velocity 4.0 MTB X-Flow Goggles certainly hold their own, with its unique design and optimum airflow. Some minor fit issues and the fact that some may prefer covered vents to prevent the ingress of trail debris notch down the score a little. But on solid trails they excel.

Swipe to scroll horizontally
The Lowdown: Leatt Velocity 4.0 MTB X-Flow Goggles
FitTight strap and slight pressure point in fit, but otherwise good★★★
PerformanceVenting is truly amazing, excellent field of vision★★★★★
LensesClarity is fantastic as is build quality★★★★★
Value for moneyGreat considering the performance★★★★

Tech specs: Leatt Velocity 4.0 MTB X-Flow Goggles

  • Price: $140 / £109.99 / €119.00
  • Extra lenses: $35.60 / £27.99 / €29.99
  • Options: Black / Stripe / Timber
  • Weight: 151g
James Blackwell
Freelance writer

James, aka Jimmer, is a two-wheeled fanatic who spent 20 years working on MBUK. Over that time he got to ride some amazing places, ride with the world's top pros and of course, test a lot of bikes and kit. Having ridden and tested everything from XC to DH, he now calls the trail/downcountry stable his happy place. Although a self-confessed race-a-phobe, it hasn’t stopped him racing XC, DH, Enduro, Marathon and the notorious Megavalanche.