All Mountain Half Shell A2 Helmet MIPS - Ventilated Trail Protection

Our review of the Troy Lee Designs A2 MIPS finds it aimed at trail riders who want a balance of ventilation, modern impact protection, and comfortable fit without the bulk of a full-face helmet. The single biggest reason to buy is its exceptional cooling: huge intake ports that are 25% larger than the prior A1, connected to large exhaust ports through deep internal channels, deliver noticeably better airflow on long climbs and hot descents. Combined with a dual-density EPS co-molded with EPP liner and the MIPS system, the A2 puts protection and comfort at the center of its design.

Key Features

• Huge ventilation: 25% larger intake ports and massive exhausts move air efficiently to keep riders cooler on sustained efforts.
• MIPS brain protection: The integrated MIPS system reduces rotational forces to the brain in some crash scenarios for added safety.
• Dual-density liner: EPS co-molded with EPP provides layered impact energy management across low and high-speed impacts.
• Frontal protection: 16% more EPS+EPP in the frontal lobe and raised EPS splines give extra coverage where impacts commonly occur.
• Comfort liner: X-Static Pure silver comfort liner offers odor control and quick-dry moisture wicking for multi-hour rides.
• Adjustable fit: A swept shell with adjustable strap and breakaway visor screws balance coverage, comfort, and trail practicality.

Who It's For

The A2 MIPS is best for mountain bikers who ride aggressive singletrack, enduro-style descents, and long trail days where both cooling and impact management matter. Riders who prioritize a ventilated half-shell that still offers enhanced frontal protection and modern rotational impact mitigation will appreciate this helmet.

Less suitable are riders who require a full-face helmet for downhill race conditions or those who want a minimalist commuter helmet with very low coverage. Also, riders seeking removable, washable liners with heavy detachable padding should verify fit against the included X-Static comfort liner.

Pros & Cons

Pros

• Exceptional ventilation from enlarged intake and exhaust ports that improve cooling on long climbs.
• MIPS system provides added rotational protection in certain crash scenarios, increasing rider safety.
• Dual-density EPS and EPP liner handles a broad range of impact energies while adding frontal lobe protection.
• X-Static Pure silver liner keeps odor down and wicks moisture for longer ride comfort.

Cons

• As a half shell, it does not provide the full-face coverage some downhill racers prefer.
• The liner is comfortable but may not be as removable or thick as some riders expect for cold-weather layering.

Specifications

Model	A2 MIPS Half Shell
Brand	Troy Lee Designs
Protection system	MIPS rotational protection
Liner	Dual-density EPS co-molded with EPP
Ventilation	Huge intake ports 25% larger than A1 with large exhaust ports
Comfort liner	X-Static Pure silver odor control, quick-dry
Additional features	Raised EPS splines, 16% more frontal EPS+EPP, breakaway visor screws

Our Verdict

The A2 MIPS is a strong choice for trail and enduro riders who want top-tier ventilation paired with contemporary impact protection. Its combination of enlarged air channels, dual-density liner and MIPS makes it good value for riders who need comfort on long rides and sensible coverage without the weight of full-face models.

Frequently Asked Questions

Does this helmet include MIPS?
Yes, the A2 comes with the integrated MIPS brain protection system to help reduce rotational forces in certain impacts.

Is the liner odor resistant?
The X-Static Pure silver comfort liner delivers high performance odor protection and quick-dry moisture wicking for extended ride comfort.

How does the ventilation compare to prior models?
Ventilation is improved: intake ports are 25% larger than the A1 and connected to large exhaust ports through deep internal channels for more efficient cooling.