Troy Lee Designs D4 Composite Mips Full Face MTB Mountain Cycling Helmet









Always Evolving
It wasn't easy to improve upon the class-leading design and function of our D3 helmet, but we made it happen. Built with an aerospace shell design and materials, we were able to get the D4 Composite helmet to 1050 grams without sacrificing any strength. MIPS C2 protection system is used to add an additional layer of safety in the event of a fall. For comfort, the D4 Comp routes cooling air through a front air intake system that flows through the polymer center and power grid side mesh keeping your head cooler during the ride. X-static® and XT2® anti-microbial/anti-odor padding keep the inside of the helmet a much nicer place to be.
Key Features:
- Intended for BMX, Downhill or All-Mountain use
- Aerospace composite shell
- Lightest Composite DH/BMX Race helmet we have ever built 1050g (+/- 50g and Size M)
- MIPS C2 brain protection system-protects against rotational impacts
- 24 total vents: 10 front intake ports, 5 overhead intake vents that channel air on top of your head and an industry leading 7 rear exhaust ports
- 3 Shell sizes and 3 EPS sizes, 6 total size ranges from XS-XXL
- Anti-Microbial/Quick Dry XT2® Quick release contoured 3D cheek pads create an anatomically optimized fit. Separately placed X-Static® & XT2® precision fit headliner with
- 7 anchor points gives you optimal fit
- EPP Collarbone impact system; a relief area reduces the forces in the center lower section of the helmet where shoulder/collarbone impacts have been known to occur
- Drawstring helmet bag included
- 3-year warranty
- CERTIFIED FOR: ASTM F1952 DH MTB, ASTM F2032 BMX, CPSC 1203, CE N1078, AS/NZS 2063
Occasionally, without notice, manufacturers change product design and/or specifications.
Troy Lee Designs D4 Helmet Size Guide
How to measure
To find the circumference of your head, place a tape measure in the centre of your forehead, wrap it around above your ears and around the back of your head. If there's a slight difference between two different sizes, always go for the tighter size.

D4 Helmet Size Chart
Size |
XS |
S |
M |
L |
XL |
XXL |
Circumference (cm) |
53 - 54 |
55 - 56 |
57 - 58 |
58 - 59 |
60 - 61 |
62 - 63 |
Circumference (Inch) |
20 7/8 - 21 1/4 |
21 5/8 – 22 |
22 3/8 – 22 3/4 |
22 ¾ - 23 1/4 |
23 5/8 – 24 |
24 3/8 – 24 3/4 |
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Troy Lee Designs D4 Composite Mips Full Face MTB Mountain Cycling Helmet
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