Troy Lee Designs A3 helmet review – top end trail lid with extended rear bumper

Refined helmet shape with dual density foam core, brain-saving MIPS liner, magnetic visor and clasp, with a new skull-hugging rear profile

Troy Lee Designs A3
(Image: © Paul Burwell)

Bike Perfect Verdict

Superb quality and finish with two shots of protective technology. Adjustable for a range of head sizes and new visor designs make this helmet fully goggle compatible. Better fitting with reduced hots spots but also cool running; a superb open face for trail riding and enduro competition.


  • +

    Fully goggle compatibility

  • +

    Nip free magnetic clasp

  • +

    Great value for a MIPS helmet

  • +

    Breakaway visor technology

  • +

    Belt and braces protection


  • -

    Foam brow pad can stick to your forehead

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    MIPS liner not as smooth rotating as some

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    Expensive in certain markets

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    This color is an acquired taste

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Troy Lee Designs manufacturers three open face helmets – the A1 and A2 and the A3 featured here. All three feature the company’s legendary attention to detail, but the A3 gets an extended rear section for greater protection and several little updates such the 3D Fidlock magnetic buckle, a fully adjustable Magnajust visor and a new silicone brow pad that’s designed to stop sweat running into your eyes. It’s safety first in more ways than one.

Our testing explained

For information on Bike Perfect's testing procedures and how our scoring system works, see our how we test page.

To see where the A3 fits in the scheme of things regarding price and performance we recommend checking out our guide to the best mountain bike helmets or best half shell helmets

Troy Lee Designs A3

The latest A3 gets deeper rear protection that other Troy Lee open face helmets (Image credit: Paul Burwell)

Design and specifications

All bike helmets use an EPS (expanded polystyrene) core and traditionally this is a single density all the way through, but recently helmet makers have switched to a dual density EPS. Troy Lee Designs' take has been to in-mould an EPP (expanded polypropylene) with a layer of EPS (expanded polystyrene) foam with the polycarbonate shell. These different closed-cell foams have different jobs in the A3 – the EPS deals with major hits, in that it acts like a crumple zone, whereas the EPP offers a bit more resilience for smaller or repetitive stuff. The EPP layer adds durability and really means you won’t have to ditch the helmet if you take a tumble.

Troy Lee Designs A3

The cradle can be adjusted to better fit the back of your skull (Image credit: Paul Burwell)

It doesn’t end there though, to deal with rotational impacts the A3 gets a B-series MIPS liner integrated into the shell. This is slightly heavier and doesn’t rotate as smoothly as the liner in the Bell Super Air Spherical we’ve tested recently ,but it still allows the helmet to move on your head during an impact, helping deflect some of the energy. The liner does take up space inside the shell, so you’ll definitely need to try the A3 for fit first.

Troy Lee Designs A3

Despite plenty of padding, the A3 has stayed pretty fresh during testing (Image credit: Paul Burwell)

Also crammed in the helmet is a large web of perforated padding. To increase forward ventilation there are three holes stamped into the padding but there’s also a Sweat Glide EVA foam brow pad to help deflect any extra perspiration. This isn’t a new idea – Mavic did a similar thing with its Crossmax helmet but there was an odour issue with that design. So far, the one in the A3 has stayed pretty fresh, although I found it can stick to your forehead when you remove the helmet leaving a slight mark.

Troy Lee Designs A3

The new visor has three riding positions and can be also lifted right up for maximum google parking space (Image credit: Paul Burwell)

Troy Lee Designs has also tweaked the visor of the A3 – it's now a Magnajust design. Basically, it has a tab that locates into three recesses on the front of the helmet but to stop it slipping out when you’re rattling down a bumpy track there’s a little magnet built into tab. It’s clunky moving between the indents but it works pretty well, and you can also flip the visor right back out of the way if you want to park your goggles underneath. Troy Lee Designs also puts a sort of invisi-tape over this area to stop the tab scratching, which is a nice touch.

There’s a channel on the back of the helmet for the goggle strap and, while it’s not the deepest, it works OK. 

Underneath the MIPS liner you’ll see three simple press studs for adjusting the height of the retention device. It’s a pretty common design but I found it can hurt your thumb pressing it back in. There’s a simple plastic dial for adjusting the 360-degree retention device, which totally encircles your head and provides a snug and secure fit.

To stop skin nipping issues, Troy Lee Designs specs the Fidlock SNAP magnetic closure on the chin strap. You can literally fling this together and it’s just as easy to uncouple. Adjustable side buckles allow a degree of fine-tuning if you have a particularly big head or just like to run the buckles low/high – they simply pull up and down, no latch to release. 

Troy Lee Designs A3

The Peace Red colorway comes with extra branding for Velosolutions' Pump For Peace initiative  (Image credit: Paul Burwell)


We’ve had mixed opinions of the fit of the Troy Lee Designs A1 and A2 helmets but the A3 is really snug without any hot spots. With the retention device snugged up it has so much hold that you could literally ride with the strap undone, not that I’d recommend that sort of behavior. The dial has a light action and while the gradients are quite large it doesn’t actually move that much when you’re adjusting it in and out.

It runs hotter than the Giro Manifest Spherical MIPS but there’s a ton of padding to soak up sweat and that Sweat Glide brow pad really does help if things get too saturated. It feels just as snug as the Giro, although I’d say the A3 has the edge on aesthetics – you do get extra kudos points for that shark fin. 

The visor is easy to adjust with one hand and stays parallel, but it’s quite noisy and doesn’t feel that smooth. This won’t matter if you’re a fit and forget sort of rider – it just feels a little rough if you’re a constant tweaker.  

Troy Lee Designs A3

The exit ports to the rear encourage air flow through the helmet  (Image credit: Paul Burwell)


Troy Lee Designs always scores points for its semi-custom colorways, attention to detail and style, but with the A3 you also get some sensible and practical features. You do pay a premium but included with the A3 helmet is a carry bag, sticker kit and spare foam brow pads. That’s not enough to gain this helmet top marks but in the UK market Troy Lee Design is currently selling the A3 at a reduced price, which makes it more attractive and that would bump our overall rating.

Tech specs: Troy Lee Designs A3 helmet

  • Price: $230 / £200 / €250
  • Weight: 425g
  • Sizes: XS, M/L, XL/XXL 
  • Colors: Amo Blue, Peace Red, Uno Water, Uno Slate Blue, Uno Red, Uno Sideways Black, Uno Black, Uno Glass Green, SRAM White, Camo Green, Gray
  • Rival products: Giro Manifest Spherical MIPS, Bell Super Air Spherical
Paul Burwell
Freelance writer

Paul has been testing mountain bikes and products for the best part of 30 years, he’s passed comment on thousands of components and bikes, from the very first 29ers and dropper posts to latest e-MTBs and electronic drivetrains. He first put pen to paper for Mountain Bike International magazine but then contributed to What Mountain Bike, Cycling Today and Cycling Weekly magazines before a  20 year stint at MBR magazine. An ex-elite level XC racer, he’s broken more bones than records but is now sustained on a diet of trail building, skills coaching and e-bike trail shredding.