Mash Fifty 50 vs Piaggio NRG

The Mash Fifty 50 passes its MOT first time more often than the Piaggio NRG: 65.6% vs 65.5%, a 0.1-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025

Metric	Mash Fifty 50	Piaggio NRG
First-time pass rate	65.6%	65.5%
Outright fail rate	23.7%	27.4%
Vs comparable bikes (age & mileage adjusted)	-10.2 pts	-6.0 pts
Engine size	49cc	49cc
Median miles at test	4,261	9,874
MOT tests analysed	131	40,458
Most common failure	lamps and reflectors	lighting and signalling

First-time outcomes on normal tests, 2005–2025. "Most common failure" is the component group with the most recorded defects on failed tests. Read pass rates against test counts: a smaller sample is noisier. Source: DVSA anonymised MOT results.

"Vs comparable bikes" is the first-time pass rate minus the rate expected for each bike's own mix of age, mileage and test class, in percentage points: positive means better than comparable bikes. How this works.

Pass rate by test year

first-time MOT pass rate in each calendar year both bikes were tested

Test year	Mash Fifty 50	Piaggio NRG
2023	81.6%	77.5%
2024	62.2%	81.9%
2025	55.3%	77.1%

Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.

MASH FIFTY 50 65.6% pass · 131 tests PIAGGIO NRG 65.5% pass · 40.5k tests

See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.