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Troy Lee Designs
D4 Polyacrylite Helmet

5 out of 5 stars
1 Review
Color:Block Charcoal/Red


Size Chart


Why We Like The Troy Lee Designs D4 Polyacrylite Helmet

When launching bike park booters or bombing primitive trails in the foothills, the Troy Lee Designs D4 Polyacrylite Helmet is one of our favorite full-face helmets to shred in. Featuring downhill-level protection, the D4 Polyacrylite helmet is a budget-oriented version of the D4 that has just as much protection as the carbon and composite models. The D4 features a front air intake system to keep us cool on hot days, and the anatomical cheek pads give us a snug fit every time. The D4 is loaded with Mips C2 protection to help reduce energy transferred from an angled impact, and impact energy is mitigated with EPs foam and the polyacrylite shell.


  • Downhill full-face helmet for mountain biking
  • Polyacrylite shell is budget-oriented but just as durable
  • Air intake system keeps your head cool
  • Mips C2 protection reduces angled forces
  • Collarbone suspension system helps protect collarbones
  • Item #TLDY1AH
Shell Material
Impact Management
Mips C2, EPS foam
front air intake system, Power Grid side mesh
Fit Adjustment
contoured 3D cheek pad
adjustable, breakaway visor screws
Full Face
Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older
Claimed Weight
2lb 8.56oz (1150g)
Manufacturer Warranty
limited 3 year

Overall Rating

5 based on 1 ratings

Review Summary

1 Stars - 0 reviews
2 Stars - 0 reviews
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4 Stars - 0 reviews
5 Stars - 1 reviews

Fits True To Size

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Runs smallTrue to sizeRuns large

What do you think about this product?


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5 out of 5 stars

April 15, 2024

Fit snug and comfortable

I've used it several times

I love this helmet. It is comfortable and there are no gaps around my face. It’s nice and light for downhill racing.

lde105192718 l

Originally reviewed on Backcountry.com