The TLD 26.1 D4 AS Polyacrylite Helmet in The Line Charcoal/White features a full-face design with visor, "Troy Lee Designs" branding, and advanced Mips brain protection—ideal for mountain biking.

TLD 26.1 D4 AS Polyacrylite Helmet size chart shows head circumferences (cm/in) and sizes from XS to XXL for The Line Charcoal/White full-face mountain bike helmet by Troy Lee Designs.

Top view of the TLD 26.1 D4 AS Polyacrylite Helmet in The Line Charcoal/White, featuring geometric patterns, ventilation holes, Mips protection, and "Troy Lee Designs" logos on both sides.

The TLD 26.1 D4 AS Polyacrylite Helmet in The Line Charcoal/White features black, white, and silver geometric stripes, "Troy Lee Designs" logos on both sides, a full-face visor, and is Mips brain protection system compatible.

The TLD 26.1 D4 AS Polyacrylite Helmet in The Line Charcoal/White is a full-face helmet with visor, ideal for mountain biking and featuring Troy Lee Designs branding and bold graphic patterns.

TLD 26.1 D4 AS Polyacrylite Helmet in The Line Charcoal/White features bold graphics, visor, ventilation openings, and Mips brain protection—perfect for motocross or mountain biking. Left side view shown.

The TLD 26.1 D4 AS Polyacrylite Helmet in The Line Charcoal/White features a geometric full-face design with visor and advanced Mips brain protection—perfect for mountain biking.

Description

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.

FEATURES
• 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

TLD 26.1 D4 AS Polyacrylite Helmet / The Line Charcoal/White

Name: TLD 26.1 D4 AS Polyacrylite Helmet / The Line Charcoal/White
Brand: Troy Lee Designs
SKU: 175047001
Price: 599.99 AUD
Availability: OutOfStock

Brand: Troy Lee Designs SKU: Click to copy the SKU and show the pick location

$599.99 AUD

Or 4 payments of $149.99 AUD with

Colour - -

Size - XS/SM

The D4 (Carbon, Composite and Polyacrylite) comes in three shells, each covering two sizes. Pick the shell that covers your measurement.

Size	Head circumference	Notes
XS-S	53–56cm	XS 53–54 · S 55–56
M-L	57–59cm	M 57–58 · L 58–59
XL-XXL	60–63cm	XL 60–61 · XXL 62–63

TLD says: if you are between sizes, consider the larger size for a more relaxed fit. Spare cheek pads and a head liner are included to fine-tune the fit.

How to measure

Wrap a soft tape measure to measure the circumference (around) your head an inch (2.54cm) above your eyebrows. Keep the tape level front to back around the widest part of your head. Keep it level and snug but not tight. If you don't have a measuring tape, use a piece of string, shoelace, spaghetti* or snake** then lay it out on a table and measure it with a ruler.

*Make sure the spaghetti is cooked or the snake is asleep.

**LUXBMX does not recommend using a snake to measure the circumference of your head. (It's a joke)

Between two sizes? Most helmet brands recommend the larger size and using the thicker set of pads. A helmet should feel snug all round with no pressure points, and shouldn't rock when you shake your head.

Read the full buying guide

The D4 (Carbon, Composite and Polyacrylite) comes in three shells, each covering two sizes. Pick the shell that covers your measurement.

Size	Head circumference	Notes
XS-S	53–56cm	XS 53–54 · S 55–56
M-L	57–59cm	M 57–58 · L 58–59
XL-XXL	60–63cm	XL 60–61 · XXL 62–63

TLD says: if you are between sizes, consider the larger size for a more relaxed fit. Spare cheek pads and a head liner are included to fine-tune the fit.