The Best All Mountain and Enduro MTB Helmets
With so many mountain bike helmet manufacturers out there offering up a whole host of features and technologies, it can be a tough task to choose the right lid. We’ve pulled together the best open-face MTB helmets from top brands including Giro, Fox, Met, POC and 661 and zoomed in on the good and the not so good of each.
In our reviews, we take a close look at the helmet’s construction, the venting, the fit, plus any other features, and we give it a rating for comfort and adjustability.
MTB Helmet Construction
Believe it or not, how good your helmet looks is only the second most important consideration. The number one thing you should be concerned about is whether your helmet will protect your melon if and when you stack it.
There are two basic types of helmet construction – in-mold and hard shell. With an in-mold helmet, the shell and EPS liner are formed in one mold and fused together at the same time. Whereas, with a hard shell helmet, the shell is cast separately to the EPS foam liner and then the two are laminated together. From a safety standpoint, they both provide the same level of EU certified protection. The main differences are that in-mold helmets provide weight and ventilation advantages, whilst hard shell helmets are generally less expensive.
Venting
It’s not ideal to have sweat pour into your eyes when negotiating a rock garden at pace. That’s why bike helmets use a system of vents to prevent overheating. More venting isn’t always better but a system that uses a combination of both fore and aft vents, along with internal passages is best.
Fit
Your helmet needs to fit your head properly if it’s going to protect you in a crash. You want to achieve an even, snug fit so there’s as little movement as possible without pressure points. Your helmet’s straps and fit system will determine how customizable the fit will be. A good fit system will allow you to raise or lower the helmet, adjust the tension around your head and fine-tune the padding for a snug fit. An adjustable chin strap will allow you to get just the right tension so your helmet is pitched just right whilst letting you move your head freely.
Here we review some of the best mountain bike helmets available:
Troy Lee Designs A1 Helmet Review
Our Rating 
RRP: 139 GBP | 161 EUR | 182 USD
Construction: In-mold – EPS liner, polycarbonate shell
Venting: 16 vents and internal channelling
Fit system: Triple position adjustable retention system
Meets European safety standard: Yes
Weight: 320 g (medium)
Comfort: Excellent
Adjustability: Excellent
Recommended use: All-Mountain, Enduro
We like:
A good looking, comfortable helmet with confidence-inspiring coverage and good adjustability. Little wonder then that more and more enduro fashionistas seem to be sporting one. Ventilation is taken care of by 8 intake passages which channel air through the lid and out of 8 vents at the rear. The reinforced polycarbonate shell is molded to the EPS liner and it’s nice to see that the shell wraps under the bottom of the EPS foam to add durability. The coverage is excellent and the A1 is up there with the best in terms of the protection offered from an open face lid. TLD have done a good job of making this helmet fit most head shapes. The straps are anchored at the sides and at the back and are fully adjustable whilst the click wheel allows you to fine tune the fit.
With its stylish design, excellent fit, peace of mind coverage and loads of different colours available, you won’t be disappointed.
We’re not so keen on:
Great coverage and thick internal padding come at a price, this is a warm helmet. Good job then that the plush interior is efficient at wicking away moisture.
Available from:
Bell Super 3 MTB Helmet Review
Our Rating
RRP: 120 GBP | 150 EUR | 165 USD
Construction: In-Mold Polycarbonate Shell
Venting: 23 vents, 4 brow ports
Fit system: TAG™ Fit System
Meets European safety standard: Yes
Weight: 390 g
Comfort: Good
Adjustability: Excellent
Recommended use: All-Mountain, Enduro
We like:
The Bell Super caters to the all-mountain contingent who need better protection than that offered by a wispy-light XC lid, but also need the versatility that comes from lid you can wear all day. This lid has that extended coverage on the back and sides that gives you a good feeling of protection and inspires confidence.
Goggle compatibility is a big issue for all-mountain and enduro riders and Bell have clearly thought about this when designing the Super. As with the Bontrager, you can flip the visor up during climbs and rest your goggles on the front of the helmet, then put your goggles back on for the descent and flip the visor back down.
The goggle strap runs directly under the visor on the side of the helmet and wraps around the back, covering one of the vents. Four ventilation channels where the top of the goggles meet the helmet is a feature taken from Bell’s full-face pedigree and works well to actively push cool air over your head whilst keeping your goggles fog free. A generous 23 vents on the helmet also help you keep a cool head.
The GoPro compatible mount plugs straight into the Super’s top vent and is secured with a Velcro strap, eliminating the need for messy double-sided sticky tape or zip-ties. It’ll also work with a Sony Action Cam or a bike light.
Bell’s tried and tested Speed Dial fit system lets you easily dial in a custom fit, and the 3.0 version is compatible with the Super 3R chin guard turning this helmet into a fully fledged full facer.
We’re not so keen on:
Although the GoPro mount feels secure, the Velcro fastening doesn’t inspire much confidence, especially when trusting it with 400 quids worth of camera gear.
The helmet fit is a bit on the small side, so you may need to go for a size up for a comfortable fit across the brow.
Available from:
Giro XAR MTB Helmet Review
Our Rating 
RRP: 108 GBP | 140 EUR | 155 USD
Construction: In-mold – EPS liner, polycarbonate shell
Venting: 17 Wind Tunnel™ vents, internal channelling
Fit system: Roc Loc® 5
Meets European safety standard: Yes
Weight: 320 g (medium)
Comfort: Excellent
Adjustability: Good
Recommended use: Cross-Country, All-Mountain, Enduro
We like:
The Giro XAR is a direct descendent of the once popular and now iconic XEN all-mountain helmet. True to its legacy, the XAR is a super lightweight and comfortable helmet with a tick firmly in the ‘all-mountain’ box.
The updated Roc Loc fit system allows you to get a snug fit with a quick twist of the dial. For a fine tune fit you can change the vertical positioning of the helmet using a three position bracket that can be adjusted without removing the helmet. Comfort is enhanced with generous anti-microbial padding which is removable and washable.
It’s well documented that Giro places a huge emphasis on safety, and the XAR extends the EPS foam standard protection with an integrated roll cage. A web of DuPont Nylon molded inside the helmet’s foam providing extra strength that you’ll never notice …unless you need it.
The visor has 15 degrees of movement so you can adjust it up and down to suit the conditions or to accommodate your eye wear.
17 vents, plus venting channels on the inside of the helmet are efficient at letting air flow over your head to keep you cool when you’re pedalling hard.
We’re not so keen on:
Although the styling is more aggressive than a standard XC lid, there’s not as much coverage as other enduro helmets. The visor is on the small side and doesn’t lock in place. The Roc Loc system works well but feels a bit flimsy, especially for the price.
Available from:
Fox Flux MTB Helmet Review
Our Rating 
RRP: 80 GBP | 90 EUR | 100 USD
Construction: In-mold Thermoformed EPS
Venting: 20 Vents
Fit system: Detox II retention system
Meets European safety standard: Yes
Weight: 408 g (medium)
Comfort: Excellent
Adjustability: Fair
Recommended use: Cross-Country, All-Mountain, Enduro
We like:
The Flux from Fox Racing is a lightweight trail helmet with aggressive all-mountain styling and a peace-of-mind deep rear profile. The Flux has established itself as Fox’s most popular open face helmet as a result of combining essential trail-riding features with comfort and ventilation at a keen price.
Coverage is slightly less than you’ll get with the Fox Striker, but the Flux does a good job of bridging the gap between XC and all-mountain. The Flux is constructed from expanded polystyrene foam with an in-mold shell and easily passes the CE safety standard. 20 big vents channel air in to keep you cool.
The Detox fit system isn’t as sophisticated as some custom fit ratchets, but it’s easy to adjust with gloved hands and it comfortably wraps the head.
Overall, the Flux is a comfortable mountain biking helmet with good ventilation and a fit system that works at a competitive price-point.
We’re not so keen on:
At 400 g, the Flux is one of the heavier lids in this line-up. Rear adjustment band feels a bit flimsy and it’s questionable whether it would stand the test of time. Unnecessary spoiler at the helmet’s rear serves no real purpose and adds bulk. Visor isn’t adjustable and is prone to popping out of place.
Available from:
POC Trabec MTB Helmet Review
Our Rating
RRP: 149 GBP | 160 EUR | 150 USD
Construction: Polycarbonate shell and EPS liner
Venting: 16 Vent Aerodynamic Ventilation
Fit system: POC Size Adjustment System
Meets European safety standard: Yes
Weight: 340 g (medium)
Comfort: Good
Adjustability: Good
Recommended use: All-Mountain, Enduro
We like:
The POC Trabec is a well-ventilated, well-built in-mold helmet with distinctive good looks. An aggressive, all-mountain design sits quite low on your head and provides extra protection across the temples and back of the head.
Ventilation is via 16 large vents evenly distributed across the shell which serve to feed air in to an internal channel system. This combined with the helmet’s light weight means your head is kept surprisingly cool.
POC’s size adjustment system operates via a band at the rear of the helmet that requires setting up for a custom fit, rather than tweaking on the fly like you can do with a dial system. The adjustment band is made from rubberised plastic that feels like it will stand the test of time.
The Trabec is a well-constructed helmet that has been built to last. We liked that the polycarbonate outer shell wraps around the EPS foam on the underside of the lid to provide an extra level of durability.
The Trabec is also available in a MIPS version that adds intelligent impact technology for an extra 60 GBP.
We’re not so keen on:
The visor is a bit small and can only be adjusted up and down a limited amount – POC could look at the Bell Super for inspiration here. The padding is a little meagre and it seems like POC have traded comfort for low weight and ventilation. The adjustment band fit system lacks the convenience of a click wheel.
Available from:
Bontrager Rally MTB Helmet Review
Our Rating
RRP: 80 GBP | 109 EUR | 99 USD
Construction: In-mold composite
Venting: 13 open vents
Fit system: Headmaster fit system
Meets European safety standard: Yes
Weight: 360 g (medium)
Comfort: Good
Adjustability: Excellent
Recommended use: All-Mountain, Enduro
We like:
The Bontrager Rally’s aggressive styling and wrap-around protection is aimed squarely at all-mountain and enduro riders. The coverage extends further down the back of the head than a standard XC lid and the in-mold construction combined with integrated visor makes for a lightweight and good looking helmet. A few thoughtful features combine to signal that this helmet was designed to be worn with goggles.
A generous number of large vents provide good airflow which is channelled over your head using a system of internal channels. It works well to keep your dome cool on the climbs.
The visor integrates nicely with the rest of the lid and can be adjusted by loosening a glove-friendly screw on each side. With the visor all the way up you can rest your goggles on the front of your helmet when not in use. The broad visor is effective at keeping the sun out of your eyes and your focus on the trail.
Bontrager’s FormFit Anti-microbial foam padding is moulded to the internal shape of the helmet and attached using velcro, so it can be removed for washing. Channels over your brow help direct airflow to stop sweat dripping into your eyes and keep goggles fog free.
Bontrager’s Headmaster fit system works well and lets you quickly and easily dial in a custom fit using a click-wheel at the rear of the helmet. You can adjust the height and circumference with one gloved hand and you can really get a snug, confidence inspiring fit.
The helmet’s chin straps is comfortable next to your face and features Bontrager’s lock down strap dividers which are very simple to open and close for quick and easy adjustability.
Overall, a top notch mtb helmet at a keen price, that’s lightweight, comfortable, looks good and should be on any all-mountain rider’s shortlist.
We’re not so keen on:
The Rally’s outer shell feels slightly less supportive than the more expensive (and heavier) Lithos. And, unlike the Lithos, the Rally doesn’t come with an integrated mounting system for camera or light, which is a shame.
