Bell 4 Forty MIPS
Tested in 2026
Adult
Mountain bike open-face
Score
71.8
out of 100
Star rating
4/5 Stars
Price
$
$
$
$
$81-$160
Performance
Specifications
Performance
Each metric is weighted differently based on crash severity. Scores combine to create the overall 100-point rating.
Helmet coverage
5.1
/ 6
Retention system strength
6.0
/ 6
Head protection in low-speed impact
6.0
/ 12
Angular head impact protection
27.6
/ 32
Head protection from concentrated impact
8.0
/ 8
Head protection in higher-speed impact
9.6
/ 12
Head protection variability in higher-speed impact
1.0
/ 2
Head protection variability in low-speed impact
0.7
/ 2
Helmet stability in a crash
4.0
/ 6
Head protection in standard-speed impact
3.7
/ 12
Head protection variability in standard-speed impact
0.3
/ 2
Total
71.8
/ 100
Specifications
Model
4 Forty MIPS
Brand
Bell
Size
S, M, L and XL
Helmet Type
Mountain bike open-face
Weight (Average from 3 sizes)
400g
Shell/Liner material
Thermoplastic Copolymer
AIMS
YES
AIMS Type
MIPS
Retention System
Quick Release
Price Range
$$ ($81-$160)
Certification standard(s)
AS/NZS2063:2008
