AJS JSM 50
The pass rate is the MOT first-time pass: a roadworthiness check of the items an MOT covers (brakes, lights, tyres, steering, structure, emissions), not a full mechanical inspection of engine or gearbox internals. It is a reliability signal, not a complete measure of mechanical reliability. What this measures.
“vs expected” adjusts for age, mileage and test class, so a cherished classic and a hard-used commuter are compared fairly. How this works.
What fails on a JSM 50
| Component group | Share of defects | Defects | % of defects |
|---|---|---|---|
| lighting and signalling |
|
43 | 24.4 |
| brakes |
|
37 | 21 |
| steering and suspension |
|
22 | 12.5 |
| lamps and reflectors |
|
18 | 10.2 |
| structure and attachments |
|
15 | 8.5 |
| suspension |
|
15 | 8.5 |
| steering |
|
10 | 5.7 |
| drive system |
|
9 | 5.1 |
| driving controls |
|
4 | 2.3 |
| body and structure |
|
3 | 1.7 |
Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects.
How rivals compare
On first-time pass rate the JSM 50 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 50.
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