Size Guide | S-One Helmets
How to Measure
Wrap a measuring tape around your head, just above your eyebrows. Note your size at the point of overlap.
S-One Lifer, Retro Lifer & Onewheel S1 Retro Helmets
The Lifer fits head circumferences from 20.5" to 23.5" (52.1 to 59.7cm). Each liner size matches one head measurement below.
| Liner Size | XS | S | M | L | XL | 2XL | 3XL |
| Head (cm) | 52.1 | 53.3 | 54.6 | 55.8 | 57.1 | 58.4 | 59.7 |
| Head (inches) | 20.5" | 21" | 21.5" | 22" | 22.5" | 23" | 23.5" |
Fit Tips
- The Lifer, Retro Lifer and the Onewheel S1 Retro all use the same shell, so this chart applies to all three.
- S1 sizes run in half-inch steps, so measure carefully and pick the size closest to your measurement.
- Certified to AS/NZS 2063, CPSC, ASTM F1492 (multi-impact) and CE EN 1078 for skate and bike.