Model report · 2005–2025
NORTON BIG FOUR
600cc
Petrol
Class 2
89.9%
first-time pass rate
1.4%
failed outright
27,461
median miles at test
69
MOT tests, 2005–2025
What fails on a BIG FOUR
failure defects by component group · advisories excluded
| Component group | Share of defects | Defects | % of defects |
|---|---|---|---|
| tyres and wheels |
|
1 | 100 |
Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects.
How rivals compare
same type, similar capacity, high test volume
On first-time pass rate the BIG FOUR beats 4 of its 4 closest rivals (KAWASAKI ZX-6R, SUZUKI GSF600, YAMAHA FZS600).
KAWASAKI
ZX-6R
78.1% pass · 174k tests
SUZUKI
GSF600
77.3% pass · 143k tests
YAMAHA
FZS600
82.6% pass · 137k tests
SUZUKI
SV650S
80.6% pass · 84.6k tests
Rivals share this bike's type and sit within ±30% of its engine capacity, ≥ 5,000 tests. Card colour = better/worse first-time pass rate than the BIG FOUR.