HJC F 100 CARBON STAN MC21
The F100 is HJC's rotational modular: the chin bar rotates back over the top of the shell rather than flipping out in front, so the helmet stays compact and balanced... Read More
The F100 is HJC's rotational modular: the chin bar rotates back over the top of the shell rather than flipping out in front, so the helmet stays compact and balanced with the front open.
An advanced fibreglass composite shell keeps the weight sensible — carbon on the Carbon SKUs — and the HJ-45 shield ships in two sizes so it matches the shell instead of overhanging it. A Pinlock lens, chin curtain and breath deflector are in the box, and the HJ-V12 sun shield drops up to 8 mm.
Features
- DOT FMVSS 218 certified
- AFC (Advanced Fiberglass Composite) shell; carbon outer shell on Carbon colorways
- Rotational chin bar — rotates back over the shell rather than flipping forward
- HJ-45 face shield in two shell-matched sizes (HJ-45a XS–M, HJ-45b L–2XL), Pinlock-ready
- Pinlock lens, chin curtain and breath deflector included
- HJ-V12 internal drop-down sun shield, up to 8 mm extended drop
- ACS Advanced Channeling Ventilation — 3 intakes, 5 exhausts
- SMART HJC compatible with pre-moulded speaker pockets
Specs
- Certification: DOT FMVSS 218
- Shell: AFC (Advanced Fiberglass Composite); carbon on Carbon colorways
- Chin bar: Rotational — rotates back over the shell
- Shield: HJ-45a / HJ-45b, Pinlock-ready, lens included
- Sun shield: HJ-V12 internal drop-down, 8 mm extended
How to measure
Wrap a cloth tape measure horizontally around the fullest part of your head, about 1 inch (2.5 cm) above the eyebrows. Repeat a few times and use the largest measurement. The chart is a starting point — always try the helmet on for final fit.
HJC size chart
| Size | Head circumference (cm) | Head circumference (inches) | Hat size |
|---|---|---|---|
| 3XS | 50-51 | 19 3/4 - 20 1/8 | 6 1/4 - 6 3/8 |
| 2XS | 52-53 | 20 1/2 - 20 7/8 | 6 1/2 - 6 5/8 |
| XS | 54-55 | 21 1/4 - 21 5/8 | 6 3/4 - 6 7/8 |
| S | 55-56 | 21 5/8 - 22 | 6 7/8 - 7 |
| M | 57-58 | 22 3/8 - 22 7/8 | 7 1/8 - 7 1/4 |
| L | 58-59 | 22 7/8 - 23 1/4 | 7 1/4 - 7 3/8 |
| XL | 60-61 | 23 5/8 - 24 | 7 1/2 - 7 5/8 |
| 2XL | 62-63 | 24 3/8 - 24 3/4 | 7 3/4 - 7 7/8 |
| 3XL | 64-65 | 25 1/8 - 25 1/2 | 8 - 8 1/8 |
| 4XL | 66-67 | 26 - 26 3/8 | 8 1/4 - 8 3/8 |
| 5XL | 68-69 | 26 3/4 - 27 1/8 | 8 1/2 - 8 5/8 |
Youth sizes
| Size | Head circumference (cm) | Head circumference (inches) |
|---|---|---|
| YS | 48-49 | 18 7/8 - 19 1/4 |
| YM | 50-51 | 19 5/8 - 20 1/8 |
| YL | 52-53 | 20 1/2 - 20 7/8 |
One official HJC chart covers all models (full-face, modular, open-face, half); size availability varies per model. cm values are canonical (verified on both official US and EU HJC sites); inch values follow the mathematically consistent EU print where the US page conflicts with its own cm column (M and L rows). Note: many retailers still publish HJC's LEGACY chart (XS 53-54 … 3XL 65-66), which disagrees with the current official chart — do not mix them. Youth chart is the official Y10 chart (EU site).
Manufacturer sizing data · verified July 8, 2026