BIKERELIABILITY Reg check
Model report · 2005–2025

MASH FIFTY

49cc Petrol Class 1
#4631 of 5428 overall #3 of 4 MASHs #209 of 456 moped bikes
71.3%
first-time pass rate
16.8%
failed outright
4,430
median miles at test
345
MOT tests, 2005–2025
-6.7pp
vs expected · age & mileage

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.

Pass rate over time

first-time pass rate by test year · 2020–2025

The FIFTY's first-time pass rate has fallen 20.4 points since 2020, 81.4% to 61.0%.

56%71%87%2020: 81.4% pass (59 tests)2021: 61.5% pass (65 tests)2022: 78.9% pass (57 tests)2023: 76.1% pass (46 tests)2024: 71.9% pass (57 tests)2025: 61.0% pass (59 tests)20202025

What fails on a FIFTY

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects
lamps and reflectors
95 51.4
structure and attachments
38 20.5
brakes
23 12.4
suspension
13 7
steering
12 6.5
audible warning (Horn)
2 1.1
wheels
2 1.1

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 FIFTY beats 3 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 FIFTY.

Compare with any bike

rival not listed above? pick any model to see it head-to-head with the Fifty

Pass rate by registration year

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

Best year to buy used: 2017 (73.0% pass). Weakest: 2018 (67.3%).

66%70%74%2017: 73.0% pass (174 tests)2018: 67.3% pass (101 tests)20172018

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.

Embed this bike

Free to embed on your site, blog or forum — a live Mash Fifty reliability card that stays up to date and links back here. More on the free API page.