Pass rates slide as bikes age, then, oddly, tick back up for the oldest.
Survivorship: only cherished, well-kept classics are still on the road.
Pass rates dip to their low around 19 years
(80.5%), then rise again for the oldest bikes, the survivors that have been
kept in good order.
First-time pass rate by bike age at test (years since first registration),
ages 3–35, minimum 5,000 tests per year. Source: DVSA anonymised MOT results.
At 3 years old, bikes pass first time 83.4% of the time.
The low point is around 19 years (80.5%), after which the curve
rises again: the survivorship effect. A 30-year-old bike still being MOT'd is, by
definition, one that's been looked after. Mileage matters more than age alone,
so see how mileage affects pass rates.