NORTON 99

600cc Petrol Class 2

#222 of 5426 overall #9 of 34 NORTONs #136 of 2787 other bikes

93.6%

first-time pass rate

1.7%

failed outright

12,718

median miles at test

767

MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2006–2016

The 99's first-time pass rate has fallen 3.7 points since 2006, 97.5% to 93.8%.

Pass rate by mileage

how the 99's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage 99 passes first time 95.5% of the time; by 50k that's 92.2%.

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 99

failure defects by component group · advisories excluded

Component group	Defects	% of defects	vs all bikes
brakes	6	27.3	0.2×
steering and suspension	5	22.7	0.2×
lighting and signalling	4	18.2	0.1×
tyres and wheels	3	13.6	0.2×
drive system	2	9.1	0.4×
driving controls	1	4.5	0.6×
tyres	1	4.5	0.2×

Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects. "vs all bikes" is how often this model's tests record a defect in the group, as a multiple of the all-bike rate.

How rivals compare

same type, similar capacity, high test volume

On first-time pass rate the 99 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 99.

Pass rate by registration year

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

Best year to buy used: 1961 (97.2% pass). Weakest: 1957 (88.9%).

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.

NORTON 99 FAQ

answers computed from the data above · terms in the glossary

Is the NORTON 99 reliable?

The NORTON 99 is more reliable than average for its class: 93.6% of its 767 MOT tests (2005–2025) passed first time, against a class average of 84.9%. That ranks it #222 of 5426 models.

What does a 99 fail its MOT on most?

brakes — 27% of all defects recorded against failed 99 tests.

What is the best year of 99 to buy used?

By first-time pass rate, 1961-registered examples do best (97.2%) and 1957 worst (88.9%). Condition and history still trump the year.

How many miles will a 99 last?

The median 99 shows 12,718 miles at test, and examples around 50k miles still pass 92.2% of the time — mileage alone rarely kills one.