BSA D14/4

175cc Petrol Class 1

#2196 of 5426 overall #61 of 62 BSAs #1359 of 2787 other bikes

86.0%

first-time pass rate

4.3%

failed outright

14,369

median miles at test

257

MOT tests, 2005–2025

Pass rate by mileage

how the D14/4's first-time pass rate falls with the odometer · class average 73.4%

A low-mileage D14/4 passes first time 92.1% of the time; by 30k that's 85.7%.

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 D14/4

failure defects by component group · advisories excluded

Component group	Defects	% of defects
lighting and signalling	7	35
tyres and wheels	5	25
brakes	4	20
steering and suspension	3	15
Items Not Tested	1	5

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 D14/4 beats 0 of its 1 closest rivals (BSA BANTAM).

BSA BANTAM 88.7% pass · 7,201 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 D14/4.

Pass rate by registration year

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

Best year to buy used: 1968 (86.1% pass). Weakest: 1968 (86.1%).

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.