Troy Lee Designs A3 Helmet Review – An In-Depth Review

The Troy Lee Designs (TLD) A3 helmet is a top-of-the-line half shell mountain bike helmet. It is packed with safety features and customization options. I have been testing the A3 for the last few months on the trails of Nelson in New Zealand, which is famous for its long climbs and steep technical descents. This Troy Lee Designs A3 helmet review will look into what’s good and what’s not, so you can make an informed decision when buying a helmet!

As a part-time MTB instructor, I was trying to find the safest possible open-face helmet to protect me during my time on a MTB. After a bit of research, I found that the TLD A3 fitted the role perfectly.

In this Troy Lee Designs A3 review, I will go through the different components of the helmet. This includes comfort, ergonomics, safety, styling, ventilation/temperature, weight, and lastly its value. I will explain my personal experience with the helmet in each component and finally my overall thoughts.

Troy Lee Designs A3 Helmet Review

Troy Lee Designs A3 MIPS
Check Latest Price On Amazon
We earn a commission if you click this link and make a purchase at no additional cost to you.


  • Very comfortable
  • 5 star safety with EPS + EPP foam layering and MIPS technology
  • Great all round head coverage
  • Easy and ergonomic features such as the Fidlock buckle and adjustable visor
  • Comes with multiple padding/customisation options


  • Relatively heavy
  • Quite warm

Comfort and Sizing

As soon as I put the A3 on my head I noticed was that it felt as though it was giving my head a big warm hug. TLD quote on their website “so comfortable you will never want to take it off” and I will have to agree with that!

There have been multiple occasions where my flatmates have arrived home to find me sitting at the table with my helmet still on my head, even though I finished my ride 45 minutes ago. It feels like your favorite old hat you’ve had for years that seems to mold to your head as if it was made for you.

Troy Lee Designs A3 Comfort
So comfortable I often forget to take it off!

The A3 helmet has great all-around coverage. It is a very deep helmet (sits quite low on your head) and it comes down quite far in all directions. It’s one of the few helmets I have tried on where I’m satisfied with the amount of protection at the back of the head, as well as around the temple. The A3 has great adjustability and customization to get the perfect fit, more on this later…

For those that are fans of the previous model, the A1, you won’t be disappointed with the A3 which is just as comfortable, if not more so!


The Medium/Large size I have been testing is recommended for heads with a circumference of 57-59 cm. For reference, my head circumference is 56-57 cm, which means I am at the lower end of the sizes.

When I tried the size XS/S on, I did not get the same feeling of great coverage and safety as I did from the M/L. If you’re bordering between sizes (and you’re unable to try the different sizes on first) I would suggest going for the larger size. 

See the size chart here.

Sweat Guide

When you buy the helmet it comes with an extra, thicker, liner and two extra “sweat glide” pads. These “sweat glide” pads sit at the front of the helmet and stop the sweat from running down your forehead into your eyes. It does this job well until you have drenched the pads. Sometimes the sweat just gets stuck in the helmet for longer, rather than running out! 

Ergonomics, Customisation and Features

Perhaps my favorite part of this helmet is its ease of use and all the customization options. You can tell everything has been well thought out and works just as it should on a premium mountain bike helmet. 


The helmet features TLD’s google friendly “3-way Magnajust visor” which clicks into place in three different positions. It is very secure in each position but yet it’s still easy to move with just one hand. There is an added option of moving the visor past its highest position, which allows full-sized goggles or sunglasses to easily fit underneath.

Troy Lee Designs A3 Visor Down
Visor right the way down
Troy Lee Designs A3 Visor Down 2
A little higher…
Troy Lee Designs A3 Visor Up 1
Almost there…
Visor at its highest setting- Can store eyewear below the visor like this

Fidlock Buckle

The A3 uses a magnetic 3D-Fidlock buckle that goes together so easily you can almost throw the two sides at each other and the magnet clicks them into place. Once together, it feels extremely secure, and only comes apart by sliding the 2 parts in opposite directions. I highly rate this feature, it’s so easy and secure, I don’t want to go back to a regular buckle ever again!

Troy Lee Designs A3 Fidlock Buckle
Fidlock Buckle is super easy to do up.

Retention System

A lesser-known feature of this helmet is the adjustable height of the rear retention system. Like many helmets, the retention system tightens at the rear with a clicky dial to bring it snug around your head.

Unlike many other helmets, the A3 has adjustable mounting points so the retention system can be moved further up or down the back of your head to create the perfect fit. I have mine set in the middle setting (stock) which fits me great.

I have experimented with moving it lower down the back of my head. However, this caused the helmet to be pushed upward when my head was tilted backward- as you do when you’re standing up, looking up the trail.

If you have this problem in the stock setting, try moving the retention system to the high setting, so it moves higher on the back of your head. This will stop the muscles in your neck from pushing up the helmet.


It is clear to see that the TLD A3 MIPS helmet has been designed with safety as a priority. It has a 3 layer shell that includes EPP, EPS foam layering and an outer hard shell. The EPP foam absorbs impact from lower speeds. The EPS foam is slightly firmer and is designed for high-speed impacts- so all your bases are covered. 

MIPS Troy Lee Designs A3

On the inside, you will find the B-Series MIPS rotational brain protection system. This system limits the rotational forces on the rider’s head, dramatically reducing the chances of a concussion or brain damage during an impact. 

This MIPS liner is integrated seamlessly into the retention system. So when you spin the clicky dial to tighten the helmet, it tightens around your head evenly, rather than just tightening from the back. As TLD puts it: “it’s a true 360-degree system”. The TLD A3 received a 5/5 star safety rating in the Virginia Tech helmet testing ratings. 

As I said earlier the A3 has great coverage and it sits deeply around your head. This provides protection from all angles, giving me the feeling of safety and security I was looking for. 


The TLD A3 features 16 ventilation holes, however, I still found myself getting a relatively hot head during the climbs. The temperatures I’ve been riding in have not been hot. I’ve been riding on mild days in a Nelson winter, somewhere around 10 or 12 degrees celsius.

Once you build your speed up it gets slightly better, as more air flows through the vents. But I still wouldn’t call it a “cool” helmet.

Troy Lee Designs A3 Ventilation


The helmet weighs in at roughly 420 grams, which is not light, however, it’s not excessively heavy either. To compare that with other high-end helmets (all size medium):

  • POC Kortla Race Mips is 390 grams,
  • Giro Manifest Spherical comes in at 360 grams and,
  • Fox Speedframe Pro comes in at 405 grams.

My previous helmet was a MET ​​Parabellum which weighed in at just 285 grams and was very well ventilated, so the difference was noticeable for me. However, the Parabellum lacked the safety features that the high-end helmets have, and hence comparing their weight would be an unfair comparison. 

I assume the extra material on the TLD A3 is what traps the heat in, but it’s also what makes it feel so safe, comfortable, and secure. It’s a trade-off and ultimately comes down to what you value more.

Personally, I don’t mind the extra heat and weight, I value the extra safety and comfort it provides. 


The styling on the helmet is great. I have the SRAM white and red version as seen in the photos. It’s the first time I have ridden with a white helmet and I’m really enjoying it. It’s visible and I’m easily identifiable. I will admit, I think some of the color options look a bit funny, but that’s up to personal preference. The rounded shape with the “shark fin” on the back gives it a unique look and I like it. 


The TLD A3 is one of the more pricey open-face helmets on the market. It is comparable with the likes of Giro’s latest Manifest helmet, or the Fox Speedframe Pro or the POC Tectal SPIN, which are all top-end helmets. While it is reasonably expensive, there is no denying that the A3 is built to extremely high standards, the levels of comfort and safety technology are class leaders.

Buying a good helmet is investing in your future health. Your head and brain are worth protecting. If you have the money, a safe helmet could be one of the best investments you will ever make. 

Final Thoughts

In summary, the Troy Lee Designs A3 is a great helmet and I really enjoy wearing it. It is expensive, but the quality makes up for it.

The Fidlock buckle and 3-way visor make this helmet very easy to use and adjust on the fly. The deep dished helmet gives full protection and is uber comfortable on your head. The MIPS cradle, combined with the 360-degree retention system, and the 3 layer shell construction provide safety to the highest standard.

The TLD A3 has great customization options with the retention height adjustment, and an extra set of thicker pads to custom fit it to your head.

The downside is that it isn’t as light as you would expect given the price, and it is not as well ventilated as some other helmets on the market. But, if safety and comfort are your top priorities, this is a helmet for you. 

If you enjoyed this Troy Lee Designs A3 review, but you want to have a check out some similar helmets- have a look at our Bell Super Air R, or Giro Source reviews.

About the reviewer:
Wilfred, or “Wolfie” as he’s known, lives in Nelson, New Zealand. Wolfie works in the local bike shop, Gravity Nelson, as a mountain bike coach and shop assistant. Before moving to Nelson he lived on the West Coast for 2 years studying a Diploma in Outdoor Adventure Education. Check out what he gets up to here! 

If you are ever planning on heading to New Zealand, and want some of the best mountain biking the country has, stay in Nelson. Check out Gravity Nelson for all your biking needs, plus shuttles, coaching and a good yarn!