Royal Alloy GP 300 S vs Piaggio X9

The Royal Alloy GP 300 S passes its MOT first time more often than the Piaggio X9: 92.4% vs 77.0%, a 15.4-point lead.

MOT reliability, side by side

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

Metric	Royal Alloy GP 300 S	Piaggio X9
First-time pass rate	92.4%	77.0%
Outright fail rate	5.0%	17.5%
Vs comparable bikes (age & mileage adjusted)	+3.1 pts	-4.4 pts
Engine size	278cc	244cc
Rank among all models	#405 of 5428	#4065 of 5428
Median miles at test	3,620	12,186
MOT tests analysed	799	21,703
Most common failure	steering	steering and suspension

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	Royal Alloy GP 300 S	Piaggio X9
Steering & suspension	2.5%	7.5%
Lights & signalling	0.9%	7.3%
Brakes	0.1%	6.5%
Tyres & wheels	1.3%	4.2%
Fuel & exhaust	0%	1.8%
Structure & body	0.1%	0.8%

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	Royal Alloy GP 300 S	Piaggio X9
2023	92.0%	80.3%
2024	93.0%	75.6%
2025	92.2%	78.4%

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	Royal Alloy GP 300 S	Piaggio X9
0k-10k miles	92.5%	81.4%
10k-20k miles	93.0%	75.8%

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

Royal Alloy GP 300 S vs Piaggio X9 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Royal Alloy GP 300 S or the Piaggio X9?

The Royal Alloy GP 300 S passes its MOT first time more often than the Piaggio X9: 92.4% vs 77.0%, a 15.4-point lead. Adjusted for age, mileage and test class, the Royal Alloy GP 300 S still comes out ahead: +3.1 points vs comparable bikes for the Royal Alloy GP 300 S, -4.4 for the Piaggio X9. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Royal Alloy GP 300 S fail its MOT on most?

Steering & suspension: 2.5% of Royal Alloy GP 300 S MOT tests failed on it, then tyres & wheels (1.3%).

What does the Piaggio X9 fail its MOT on most?

Steering & suspension: 7.5% of Piaggio X9 MOT tests failed on it, then lights & signalling (7.3%).

ROYAL ALLOY GP 300 S 92.4% pass · 799 tests PIAGGIO X9 77.0% pass · 21.7k tests

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