BIKERELIABILITY Reg check
League table/ NORTON/50
Model report · 2005–2025

NORTON 50

350cc Petrol Class 2
#567 of 5428 overall #22 of 34 NORTONs #344 of 2788 other bikes
91.5%
first-time pass rate
0.8%
failed outright
19,595
median miles at test
365
MOT tests, 2005–2025

The pass rate is the MOT first-time pass: a roadworthiness check of the items an MOT covers (brakes, lights, tyres, steering, structure, emissions), not a full mechanical inspection of engine or gearbox internals. It is a reliability signal, not a complete measure of mechanical reliability. What this measures.

Pass rate over time

first-time pass rate by test year · 2006–2011

The 50's first-time pass rate has fallen 8.2 points since 2006, 95.0% to 86.8%.

85%91%97%2006: 95.0% pass (40 tests)2007: 90.7% pass (43 tests)2008: 91.9% pass (37 tests)2009: 90.3% pass (31 tests)2011: 86.8% pass (38 tests)20062011

Pass rate by mileage

how the 50's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage 50 passes first time 85.7% of the time; by 30k that's 97.7%.

83%92%100%0k: 85.7% pass (105 tests)10k: 95.1% pass (81 tests)20k: 90.6% pass (53 tests)30k: 97.7% pass (43 tests)0k20k30k

First-time pass rate by odometer reading at test, 10,000-mile bands for this model. Mileage is the strongest reliability signal. See the full curve.

What fails on a 50

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects
lighting and signalling
6 46.2
steering and suspension
3 23.1
Items Not Tested
2 15.4
brakes
1 7.7
tyres and wheels
1 7.7

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 50 beats 4 of its 4 closest rivals (SUZUKI AN400, SUZUKI DR-Z400S, YAMAHA RD350).

SUZUKI AN400 86.2% pass · 27.1k tests Compare head-to-head →
SUZUKI DR-Z400S 80.4% pass · 26.8k tests Compare head-to-head →
YAMAHA RD350 86.3% pass · 19.6k tests Compare head-to-head →
KAWASAKI ZXR400 73.1% pass · 14.2k tests Compare head-to-head →

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 50.

Compare with any bike

rival not listed above? pick any model to see it head-to-head with the 50

More NORTON models

other NORTON bikes ranked by MOT pass rate
NORTON COMMANDO 90.8% pass · 12.3k tests
NORTON DOMINATOR 92.6% pass · 3,807 tests
NORTON ES2 91.3% pass · 2,223 tests
NORTON COMMANDER 91.6% pass · 2,094 tests
NORTON TRITON 92.1% pass · 1,496 tests
NORTON ATLAS 92.5% pass · 1,153 tests

See all NORTON models →

Pass rate by registration year

how each model-year cohort fares · registration year from first use date

Best year to buy used: 1960 (89.0% pass). Weakest: 1959 (88.9%).

88%89%90%1959: 88.9% pass (72 tests)1960: 89.0% pass (82 tests)19591960

First-time pass rate by the year each bike was first registered (cohorts with ≥ 50 tests). Older cohorts are survivors: the worst examples have already left the road, which tends to lift the earliest years.

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