















Troy Lee Designs - D4 Polyacrylite Fifty-50 MIPS Helmet (MTB)
Troy Lee Designs - D4 Polyacrylite Fifty-50 MIPS Helmet (MTB)
D4 Polyacrylite Fifty-50 MIPS Helmet is a Troy Lee Designs mountain bike helmet built for trail riders. The D4 platform is known for downhill-focused coverage and a locked-in feel when the terrain gets steep and fast. The Polyacrylite shell helps keep the price more approachable while still delivering the coverage riders expect. The Fifty-50 treatment gives this helmet a more individual feel than a plain solid option. The MIPS-equipped build adds another layer of confidence for riders who prioritize modern helmet technology.
The fit is aimed at riders who need their MTB helmet to stay composed on technical descents while still feeling comfortable during transitions, climbs, and longer days outside.
Why We Like It: it balances mountain bike protection with the kind of ventilation and fit that keeps longer rides from feeling like work.
Why It’ll Work for You: This is a strong pick when you want a mountain bike helmet that feels at home on everything from rough local descents to destination riding.
Variants / Options: multiple sizes and colorways available; check the selector for current stock.
Key Features:- The reigning king of full-face helmets, the D4 range expands with a Polyacrylite model packing the same safety and comfort features as the premium carbon and composite models into a price-conscious shell. Details make the D4 the most coveted full-face in mountain biking, including Mips® C2 brain protection, an air intake system for ventilation, and an unmatched anatomical fit.
- Mips® C2 Rotational Impact Brain Protection System
- Advanced Polyacrylite shell construction
- Front air intake system, with high flow through polymer center and power grid side mesh
- Collarbone Suspension System
- Breakaway visor screws
- Anti-microbial padding
- Quick release contoured 3D cheek pads for anatomically optimized fit
Original: $280.00
-70%$280.00
$84.00Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
Troy Lee Designs - D4 Polyacrylite Fifty-50 MIPS Helmet (MTB)
D4 Polyacrylite Fifty-50 MIPS Helmet is a Troy Lee Designs mountain bike helmet built for trail riders. The D4 platform is known for downhill-focused coverage and a locked-in feel when the terrain gets steep and fast. The Polyacrylite shell helps keep the price more approachable while still delivering the coverage riders expect. The Fifty-50 treatment gives this helmet a more individual feel than a plain solid option. The MIPS-equipped build adds another layer of confidence for riders who prioritize modern helmet technology.
The fit is aimed at riders who need their MTB helmet to stay composed on technical descents while still feeling comfortable during transitions, climbs, and longer days outside.
Why We Like It: it balances mountain bike protection with the kind of ventilation and fit that keeps longer rides from feeling like work.
Why It’ll Work for You: This is a strong pick when you want a mountain bike helmet that feels at home on everything from rough local descents to destination riding.
Variants / Options: multiple sizes and colorways available; check the selector for current stock.
Key Features:- The reigning king of full-face helmets, the D4 range expands with a Polyacrylite model packing the same safety and comfort features as the premium carbon and composite models into a price-conscious shell. Details make the D4 the most coveted full-face in mountain biking, including Mips® C2 brain protection, an air intake system for ventilation, and an unmatched anatomical fit.
- Mips® C2 Rotational Impact Brain Protection System
- Advanced Polyacrylite shell construction
- Front air intake system, with high flow through polymer center and power grid side mesh
- Collarbone Suspension System
- Breakaway visor screws
- Anti-microbial padding
- Quick release contoured 3D cheek pads for anatomically optimized fit























