Runs small, size up 1-2 sizes based on our 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.
Overall rating: 4.0 / 5 from 9 reviews.
Review topics: ["fit","helmet"].
"My only complaint is that there was no instructions, or what the wires are for that came with it."
"The heated shield works very well so far, it surprised me how well it works - it even defrosts and slowly clears up if I plug it in after getting condensation when not plugged in. The plug connection is a little weird where it connects to the helmet, but I think it's made to hold it in place. The helmet is maybe slightly on the tight side (I normally wear an XL and got an XL), it slides on great with no balaclava on, but a little tight getting it on when I have a balaclava on, but feels fine once it's on."
"A good helmet for your purpose. The heating works as it should."
"super light, fit the same as all the other 509 helmets i have. zero leakage which is what i was looking for. only negative for me was how hard it is to get the shield up. other than that very happy with it"
"If this was made in a modular design I would buy one"
"Order this for my husband. It’s a beautiful helmet. But it’s not true to size. My husband ordered one without me knowing. He tried on a 2X in another style, which fit perfectly. When he tried this on, it was super tight on him, which is unfortunate because he actually liked this one better."
"Very uncomfortable. Hurts your ears while putting it on not near the quality and comfort of CKX mission"
"Nice helmet!"
"I love the helmet, the size is on the tighter side compared to other 509 helmets though."
