Free US Shipping
We offer Free Shipping on all orders over $99 within the US (excludes Alaska). During select promotions & holidays we will offer Free Shipping on all orders within the US.
With 509 You Get
100% Secure Checkout
At 509 we use the best SSL certificate and the most trusted payment processors provided by Shopify Payments.
Sacrifice nothing with the next-generation comfort and performance of the bestselling 509 Altitude 2.0 Offroad Carbon Fiber Pro Helmet. Elevated in every respect, it features the MIPS Brain Protection System for the highest levels of safety. Hand lay-up carbon fiber composite construction makes it lighter, stronger, and sleeker than anything before it. A precisely engineered fit and innovative venting keep you cool and comfortable while the Fidlock® magnetic strap buckle makes for easy one-handed operation.
Key Features
- Hand Lay-up Carbon Fiber 3K Shell – Ultimate protection in a lightweight option
- Pro MIPS® Brain Protection System for ultimate safety → Learn More
- Upper vents for optimal airflow - Hi-Flow
- Nine intake vents and four exhaust vents for optimal airflow
- Fidlock® The Fidlock System is a cutting-edge magnetic chinstrap buckle used in motorsport helmets ensuring quick, secure, closures with one hand and is DOT and ECE compliant.chinstrap strap closure for easy in and out
- Moisture wicking removable Liner & Cheek pads for custom fit adjustments and easy to wash → Shop Cheek Pads for Altitude 2.0 Helmets
- Replaceable polycarbonate visor
- Universal camera mount capable
- WARNING for California Residents
Specs
- Helmet Certification: DOT
- Starting Weight: 1100 grams
- Best Head Shape: Intermediate oval fit
- Size Range: from XS to 2X
- Shell Breaks:
Small Shell - XS, SM
Medium Shell - MD, LG, XL
Large Shell - 2X, 3X, 4X
- Items Included 509 Basic Helmet Bag, 509 Drawstring Helmet Bag, Chinbar Vent Plugs, Chin Curtain, 509 Sticker
Size Guide
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.
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.
