BSA B33

500cc Petrol Class 2

#505 of 5426 overall #22 of 62 BSAs #309 of 2787 other bikes

91.8%

first-time pass rate

2.9%

failed outright

11,124

median miles at test

1,120

MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2005–2015

The B33's first-time pass rate has fallen 5.4 points since 2005, 92.5% to 87.1%.

Pass rate by mileage

how the B33's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage B33 passes first time 92.7% of the time; by 50k that's 88.4%.

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 B33

failure defects by component group · advisories excluded

Component group	Defects	% of defects	vs all bikes
lighting and signalling	33	44.6	0.3×
steering and suspension	14	18.9	0.3×
brakes	11	14.9	0.2×
tyres and wheels	9	12.2	0.4×
fuel and exhaust	2	2.7	0.2×
lamps and reflectors	1	1.4	0.1×
body and structure	1	1.4	0.2×
drive system	1	1.4	0.1×
Items Not Tested	1	1.4	1.0×
suspension	1	1.4	0.1×

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 B33 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 B33.

Pass rate by registration year

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

Best year to buy used: 1960 (97.4% pass). Weakest: 1957 (87.3%).

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.

BSA B33 FAQ

answers computed from the data above · terms in the glossary

Is the BSA B33 reliable?

The BSA B33 is more reliable than average for its class: 91.8% of its 1,120 MOT tests (2005–2025) passed first time, against a class average of 84.9%. That ranks it #505 of 5426 models.

What does a B33 fail its MOT on most?

lighting and signalling — 45% of all defects recorded against failed B33 tests.

What is the best year of B33 to buy used?

By first-time pass rate, 1960-registered examples do best (97.4%) and 1957 worst (87.3%). Condition and history still trump the year.

How many miles will a B33 last?

The median B33 shows 11,124 miles at test, and examples around 50k miles still pass 88.4% of the time — mileage alone rarely kills one.