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Troy Lee Designs Flowline MIPS helmet review

Is the Flowline MIPS the A3 killer?

Our rating 
4.5 out of 5 star rating 4.5
GBP £100.00 RRP
Troy Lee Designs Flowline MIPS

Our review

A great, stylish helmet with plenty of protection and comfort at a brilliant price
Pros: Sleek TLD style; 5-star Virginia Tech rating; impressive comfort and fit; great price
Cons: MIPS liner can be a bit noisy; missing some helpful features
Skip to view product specifications

Troy Lee Designs recently released two new trail helmets, the Flowline MIPS and Flowline SE MIPS. The former is the cheaper model and is designed to offer Troy Lee Designs’ styling and tech at a more affordable price.


The Flowline MIPS, as the name indicates, gets MIPS protection, a single-density EPS foam, in-mould construction, and an adjustable cradle and peak.

The helmet’s redesigned shape is intended to boost ventilation, while comfort is outstanding.

Troy Lee Designs Flowline MIPS helmet details

The MIPS liner in the Flowline can squeak when moved, but it’s quiet when riding. The padding is plush and plentiful.
Steve Behr

The Flowline MIPS uses a plastic shell with full wrap-in-mould construction to give plenty of protection to the underlying foam, hopefully preventing damage from everyday scuffs and scrapes.

To add cost-effective protection, the Flowline MIPS uses a single-density EPS foam to guard against high-speed impacts.

It also uses a MIPS B-series liner, where a Boa-style ratchet is attached directly to the MIPS liner to help provide a more comfortable and secure fit. The MIPS liner’s role remains the same – to reduce rotational impact forces.

Troy Lee Designs has refined the shape of the Flowline MIPS to include air vents above the brow. These allow direct airflow into the front of the helmet. While the vents aren’t the biggest compared to other brands’ designs, it’s an improvement over its Troy Lee Designs A3 helmet, which doesn’t feature them.

The Flowline MIPS features 14 vents in total, to help keep you cool.

The padding inside is removable for washing, but TLD makes no claims that it’s anti-bacterial or odour resistant, as some other helmet brands do.

The 360-degree retention system is integrated into the MIPS liner. The cradle has a three-position height adjustment to fine-tune where it sits against the back of your head.

The cradle at the rear is adjustable and comfortable, and there’s good coverage that extends down the back of your head.
Steve Behr

The peak also features three adjustment positions to fine tune its function for reducing sun glare or rain ingress.

The Flowline MIPS is relatively simplistic in its design and doesn’t feature any dedicated storage for your glasses, mounts for lights, or an action camera or crash sensors.

This helmet scores an impressive 5-star safety rating from Virginia Tech and comes in at just £100. There are three sizes available: XS/S (53-55cm), M/L (57-59cm) and XL/2XL (60-63cm), with a size-small weighing 357g.

Troy Lee Designs Flowline MIPS helmet performance

The Flowline MIPS is a smart-looking helmet with a good safety rating and an excellent price.
Steve Behr

The sharp and sleek design means the Flowline MIPS doesn’t have a bulky appearance, and it fits smartly into its trail bike design brief. It’s not the lightest helmet, but it isn’t portly either.

Coverage is good, with plenty of drop to the temples and reasonable extension down the back of the head.

The Flowline MIPS has some of the comfiest padding around, and it cradled my head with a plush feel and no pressure points. I could ride all day without having to adjust the cradle tension, and most of the time forgot I was wearing it.

I set the cradle to its lowest position, but I’m at the upper end of the helmet’s sizing chart, so that makes sense. The straps were comfortable and didn’t get in the way or annoy me.

When riding even the roughest trails, the helmet stayed in place and didn’t rattle around. The MIPS liner remained quiet in use, but did squeak when moved manually.

Once riding, I couldn’t tell why the Flowline MIPS is £120 less expensive than the TLD A3.

The Flowline scores highly for its compatibility with glasses. I didn’t find any mountain bike glasses that interfered with the helmet, or caused unwanted pressure points. I never had to stop and adjust anything once I was riding.

It would be nice to see a dedicated glasses storage system, but that would likely add to the price.

The Flowline MIPS is cooler that Troy Lee’s A3 thanks to better ventilation.
Steve Behr

The ventilation is better than the Troy Lee A3, but it’s not class-leading when compared to the Specialized Ambush 2, for example. However, it’s effective and does an admirable job of cooling your head.

It doesn’t feature the TLD A3’s sweat-management foam, but hopefully the plush padding will help soak up the worst sweat. The fact that the padding can be removed and washed is a bonus, too.

The adjustable peak may be useful, but I set it to its highest position and left it there for testing. In lower positions, it comes into vision when riding, which I don’t like. There’s just enough space underneath to stash your glasses.

How does the Troy Lee Designs Flowline MIPS helmet compare to the Bell Super Air Spherical MIPS?

It’s more than twice the price, but is the Bell better on the trails? The comfort from both helmets is top-notch and it’s hard to call which is better.

The ventilation and price are better on the TLD. However, the MIPS Spherical tech on the Bell feels more robust and sturdier than the MIPS liner on the Flowline. Both have 5-star ratings from Virginia Tech. While the Bell is a brilliant helmet, the TLD Flowline is hard to argue against in terms of price and function.

Troy Lee Designs Flowline MIPS helmet bottom line

Troy Lee Designs has made some of the most comfortable mountain bike helmets around, and the Flowline MIPS continues that trend. Its protection is impressive, as are the functionality and price.


It’s missing a few high-spec details, but these go unnoticed once you’re thrashing down the trail. For its balance of price and performance, the Flowline seems tough to beat. Plus, you get TLD style.

How we tested

These helmets make up our 2023 trail helmets group test.

We tested nine open-face lids from a range of brands, featuring different tech and takes on performance and comfort to see who came up with the goods.

Product Specifications


Price GBP £100.00
Weight 357g (XS/S)
What we tested Troy Lee Designs Flowline MIPS
Year 2023
Brand Troy lee designs


Features MIPS, adjustable retention cradle, adjustable peak
Helmet type Mountain bike open face
Smart helmet no