Pass rate over time
The JSM's first-time pass rate has fallen 4.4 points since 2017, 55.6% to 51.2%.
What fails on a JSM
| Component group | Share of defects | Defects | % of defects | vs all bikes |
|---|---|---|---|---|
| lamps and reflectors |
|
217 | 30.8 | 11.1× |
| brakes |
|
128 | 18.2 | 2.9× |
| suspension |
|
124 | 17.6 | 18.1× |
| structure and attachments |
|
117 | 16.6 | 17.8× |
| steering |
|
49 | 7 | 17.3× |
| lighting and signalling |
|
24 | 3.4 | 0.6× |
| steering and suspension |
|
17 | 2.4 | 0.6× |
| audible warning (Horn) |
|
10 | 1.4 | 9.1× |
| tyres |
|
10 | 1.4 | 2.2× |
| drive system |
|
8 | 1.1 | 1.6× |
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
On first-time pass rate the JSM beats 0 of its 4 closest rivals (PEUGEOT SPEEDFIGHT, PIAGGIO ZIP, PIAGGIO NRG).
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 JSM.
Pass rate by registration year
Best year to buy used: 2017 (69.1% pass). Weakest: 2018 (51.4%).
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.
AJS JSM FAQ
Is the AJS JSM reliable?
The AJS JSM is less reliable than average for its class: 56.4% of its 599 MOT tests (2005–2025) passed first time, against a class average of 73.4%. That ranks it #5312 of 5426 models.
What does a JSM fail its MOT on most?
lamps and reflectors — 31% of all defects recorded against failed JSM tests.
What is the best year of JSM to buy used?
By first-time pass rate, 2017-registered examples do best (69.1%) and 2018 worst (51.4%). Condition and history still trump the year.