BIKERELIABILITY Reg check
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Moto Roma Roadrunner 50 vs Piaggio NRG

The Moto Roma Roadrunner 50 passes its MOT first time more often than the Piaggio NRG: 72.3% vs 65.5%, a 6.8-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Moto Roma Roadrunner 50 Piaggio NRG
First-time pass rate 72.3% 65.5%
Outright fail rate 20.0% 27.4%
Vs comparable bikes (age & mileage adjusted) -1.5 pts -6.0 pts
Engine size 49cc 49cc
Rank among all models #4556 of 5428 #4992 of 5428
Median miles at test 6,860 9,874
MOT tests analysed 701 40,458
Most common failure lighting and signalling 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.

What fails, side by side

share of each bike's MOT tests that failed on the component · lower is better
Component Moto Roma Roadrunner 50 Piaggio NRG
Lights & signalling 9.4% 15.0%
Steering & suspension 8.1% 15.5%
Brakes 8.1% 10.2%
Tyres & wheels 3.6% 4.7%
Fuel & exhaust 2.6% 3.8%
Structure & body 0.7% 2.5%

A test that fails on two components counts once in each. Component links go to the bikes most likely to fail on it.

Pass rate by test year

first-time MOT pass rate in each calendar year both bikes were tested
Test year Moto Roma Roadrunner 50 Piaggio NRG
2006 75.4% 64.7%
2007 74.5% 63.9%
2008 73.3% 65.2%
2009 68.4% 62.2%
2010 71.2% 63.2%
2011 58.5% 63.9%
2012 82.5% 63.4%

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

Pass rate by mileage

first-time MOT pass rate by miles on the clock at test
Mileage Moto Roma Roadrunner 50 Piaggio NRG
0k-10k miles 75.1% 71.3%
10k-20k miles 64.5% 60.6%

Bands with fewer than 30 tests for either bike are left out.

Moto Roma Roadrunner 50 vs Piaggio NRG FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Moto Roma Roadrunner 50 or the Piaggio NRG?

The Moto Roma Roadrunner 50 passes its MOT first time more often than the Piaggio NRG: 72.3% vs 65.5%, a 6.8-point lead. Adjusted for age, mileage and test class, the Moto Roma Roadrunner 50 still comes out ahead: -1.5 points vs comparable bikes for the Moto Roma Roadrunner 50, -6.0 for the Piaggio NRG. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Moto Roma Roadrunner 50 fail its MOT on most?

Lights & signalling: 9.4% of Moto Roma Roadrunner 50 MOT tests failed on it, then steering & suspension (8.1%).

What does the Piaggio NRG fail its MOT on most?

Steering & suspension: 15.5% of Piaggio NRG MOT tests failed on it, then lights & signalling (15.0%).

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