BIKERELIABILITY
MOT DATA · GREAT BRITAIN · 2005–2025
League table/ AJS/31CSR
Model report · 2005–2025

AJS 31CSR

650cc Petrol Class 2
#524 of 5426 overall #8 of 45 AJSs #321 of 2787 other bikes
91.7%
first-time pass rate
2.0%
failed outright
21,958
median miles at test
254
MOT tests, 2005–2025

Pass rate by mileage

how the 31CSR's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage 31CSR passes first time 94.9% of the time; by 30k that's 84.3%.

82%90%97%0k: 94.9% pass (78 tests)10k: 92.1% pass (38 tests)20k: 91.7% pass (36 tests)30k: 84.3% pass (51 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 31CSR

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects
lighting and signalling
2 33.3
steering and suspension
2 33.3
tyres and wheels
2 33.3

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 31CSR beats 4 of its 4 closest rivals (KAWASAKI ZX-6R, SUZUKI GSF600, YAMAHA FZS600).

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 31CSR.

Pass rate by registration year

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

Best year to buy used: 1961 (93.8% pass). Weakest: 1960 (90.0%).

89%92%95%1960: 90.0% pass (50 tests)1961: 93.8% pass (80 tests)19601961

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.