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Bell 4Forty Air MIPS Fasthouse MTB Helmet

$229.99
In stock
Only %1 left
Stock #
977001
Mag-9, Moto-9, Moto-10, Revolver EVO, Rogue
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 54 - 55 6 3/4 - 6 7/8 45
S 55 - 56 6 7/8 - 7 40
M 57 - 58 7 1/8 - 7 1/4 40
L 58 - 59 7 1/4 - 7 3/8 35
XL 60 - 61 7 1/2 - 7 5/8 35
2XL 62 - 63 7 3/4 - 7 7/8 30

 

Custom 500, Moto-3, Qualifier, Riot, Scout
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 53 - 54 6 3/4 - 6 7/8 50
S 55 - 56 6 7/8 - 7 40
M 57 - 58 7 1/8 - 7 1/4 50
L 59 - 60 7 1/4 - 7 3/8 40
XL 61 - 62 7 1/2 - 7 5/8 45
2XL 63 - 64 7 3/4 - 7 7/8 35
3XL 65 - 66 8 - 8 1/4 35

 

Star, Pro Star, Race Star
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 53 - 54 6 5/8 - 6 3/4 35
S 55 - 56 6 7/8 - 7 35
M 57 - 58 7 1/8 - 7 1/4 35
L 59 - 60 7 3/8 - 7 1/2 35
XL 61 - 62 7 5/8 - 7 3/4 40
2XL 63 - 64 7 7/8 - 8 35

 

Bullitt
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 54 - 55 6 3/4 - 6 7/8 35
S 55 - 56 6 7/8 - 7 30
M 57 - 58 7 1/8 - 7 1/4 30
L 58 - 59 7 1/4 - 7 3/8 25
XL 60 - 61 7 1/2 - 7 5/8 30
2XL 62 - 63 7 3/4 - 7 7/8 25

 

RS-2
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 54 - 55 6 3/4 - 6 7/8 30
S 55 - 56 6 7/8 - 7 35
M 57 - 58 7 1/8 - 7 1/4 30
L 58 - 59 7 1/4 - 7 3/8 35
XL 60 - 61 7 1/2 - 7 5/8 30
2XL 62 - 63 7 3/4 - 7 7/8 35

 

MX-9
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 53 - 54 6 5/8 - 6 3/4 40
S 55 - 56 6 7/8 - 7 35
M 57 - 58 7 1/8 - 7 1/4 40
L 59 - 60 7 3/8 - 7 1/2 35
XL 61 - 62 7 5/8 - 7 3/4 35
2XL 63 - 64 7 7/8 - 8 30

 

Pit Boss
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
XS 53 - 56 6 7/8 - 7 50
S 53 - 56 6 7/8 - 7 40
M 56 - 58 7 1/8 - 7 1/4 50
L 58 - 60 7 1/4 - 7 3/8 40
XL 61 - 63 7 1/2 - 7 5/8 45
2XL 61 - 63 7 1/2 - 7 5/8 35
3XL 63 - 64 7 7/8 - 8 1/4 35

 

SRT
Size Circumference (cm) Hat Size (in) Cheek Pad Size (mm)
XS 53 - 54 6 5/8 - 6 3/4 40
S 55 - 56 6 7/8 - 7 35
M 57 - 58 7 1/8 - 7 1/4 40
L 59 - 60 7 3/8 - 7 1/2 35
XL 61 - 62 7 5/8 -7 3/4 35
2XL 63 - 64 7 7/8 - 8 30
3XL 65 - 66 8 1/8 - 8 1/4 25

 

Moto-9 Youth
Size Circumference (cm) Hat size (in) Cheek Pad Size (mm)
S/M 49-51 6 1/8 - 6 3/8 60
L/XL 51-53 6 3/8 - 6 5/8 50

Sizing information is provided by the manufacturer and does not guarantee a perfect fit. Please use this chart as a guide only.

Trail life

The 4Forty Air MIPS is equipped with pro-level features designed with the privateer in mind. With a sleek new shell and 3-position visor, the benefits aren't just visibly rad but functionally significant for increased air ventilation, effective sweat management, and better goggle compatibility.

Bell's Float Fit™ system, built-in Sweat Guide™, and Ionic+™ padding ensures all-day comfort, while MIPS Evolve® and extended hard-shell coverage help you stay committed in all shred conditions. Upgrades like eyewear ports, a Fidlock® magnetic buckle, and premium straps make the 4Forty Air MIPS your go-to for daily trail riding.

MIPS® EVOLVE

MIPS Evolve is designed to reduce rotational forces that can result from certain impacts. By integrating the MIPS slip plane into the retention system, Bell is able to reduce complexity and weight for a compact, better ventilated helmet that fits more closely to the head.

Float Fitâ„¢

A minimalist, lightweight fit system with an easy-to-turn rubber overmolded dial for adjustments (integrated with MIPS®).

Fidlock® Magnetic Buckle

Fidlock® is an easy-to-use magnetic buckle. This time-saving feature slides closed laterally for an effortless, secure fit.

No-Twist Tri-Glidesâ„¢

Quick-adjust fasteners that help keep straps flat and properly positioned.

Sweat Guideâ„¢

Sweat Guide pad design pulls moisture away from the brow pad and away from eyewear.

Ionic+ â„¢ Antimicrobial Comfort Padding

Quick-drying interior padding helps manage sweat while using silver for odor control.

3-Position Adjustable Visor.

Allows for sun protection and integrates easily with goggles or glasses.

Goggle Gripper

Rubber grip on the back of the helmet keeps your goggle strap in place.

Eyewear Storage

Easily stash your glasses using the integrated helmet notches.

Specifications:

  • Impact Management: MIPS® Evolve
  • Circumference: 52 – 56 cm
  • Construction: Fusion In-Mold Polycarbonate Shell
  • Visor: 3-Position Adjustable Visor
  • Fit System: Float Fitâ„¢ With Fidlock® Buckle
  • Product Weight: 360 g (Size M)
  • Certification: Complies With The Us Cpsc Safety Standard For Bicycle Helmet For Persons Age 5 And Older
More Information
Stock # 977001
Brand Bell Helmets

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