You're going to LOVE the fit. Try it on and experience our perfect fit. If you don't love it, send it back in new and unused condition within 30 days for an exchange or full refund*. Risk free.
Free US Shipping
We offer Free Shipping on all orders over $99 within the US. During select promotions & holidays we will offer Free Shipping on all orders within the US.
3 Year Warranty
We stand behind our products – with a 3 year warranty against materials and workmanship for all helmets.
100% Secure Checkout
At 509 we use the best SSL certificate and the most trusted payment processors provided by Shopify Payments.
Destroy all forms of dirt with the next-generation comfort and performance of the bestselling 509 Altitude 2.0 Offroad Carbon Fiber Helmet. Hand lay-up carbon fiber composite construction makes it lighter, stronger, and sleeker than anything before it. A larger chinbar intake plus upper exhaust vents keep you cool no matter how heated the session gets. Top of the line in every way, it includes the Fidlock® magnetic strap buckle for easy one-handed operation, plus GoPro® mounting capability.
Key Features
- Lightweight, durable hand-laid carbon fiber construction
- Fidlock® chinstrap strap closure for easy in and out
- ECE 22.05 certified
- Upper vents for optimal airflow - Hi-Flow
- Go-Pro® mounting capability → Shop Universal Helmet Camera Mount
- Perfect fit between helmet eyeport and 509 goggles → Shop All Dirt Bike Goggles
- Adjustable visor with Lifetime Warranty
- 3 Shell Design for XS to 4X Sizing
- 509 helmet bag included
- WARNING for California Residents
Specs
- Starting Weight: 1070 grams
Size Guide
Not sure about your size? Try on at your local dealer!
*Street Helmets are a tighter fit due to cheekpad compression, however, they do pack out over time/use.
How to Measure
When measuring your head, use a cloth tape. Start it just above your eyebrows and circle it around the thickest point in the rear of your head and then reference the size guide below.
Scroll to the right to see more sizes
| Size | US Hat Size | Inches | Centimeters |
| X-Small | 6 5/8 - 6 3/4 | 20 7/8 - 21 1/8 | 53 - 54 |
| Small | 6 7/8 - 7 | 21 5/8 - 21 7/8 | 55 - 56 |
| Medium | 7 1/8 - 7 1/4 | 22 1/2 - 22 5/8 | 57 - 58 |
| Large | 7 3/8 - 7 1/2 | 23 1/4 - 23 1/2 | 59 - 60 |
| X-Large | 7 5/8 - 7 3/4 | 24 - 24 1/4 | 61 - 62 |
| 2X-Large | 8 | 24 3/4 - 25 | 63 - 64 |
| 3X-Large | 8 3/4 | 25 1/4 - 25 3/4 | 64 - 65 |
| 4X-Large | 9 | 26 - 26 1/4 | 66 - 67 |
| Youth Small | 6 | 18 1/8 - 18 7/8 | 47 - 48 |
| Youth Medium | 6 1/8 - 6 1/4 | 19 1/4 - 19 5/8 | 49 - 50 |
| Youth Large | 6 3/8 - 6 1/2 | 20 - 20 1/2 | 51 - 52 |
Pressure Points
When trying on a helmet, take note of any pressure points on your forehead—a sign that the helmet is too round. Pressure points on the sides of your head indicate a helmet is too oval for the shape of your head. After you buy a new helmet, try wearing it for 30 to 45 minutes to check for pressure points before using it on a ride.
Pressure Points
When trying on a helmet, take note of any pressure points on your forehead—a sign that the helmet is too round. Pressure points on the sides of your head indicate a helmet is too oval for the shape of your head. After you buy a new helmet, try wearing it for 30 to 45 minutes to check for pressure points before using it on a ride.
