Data as of: DVSA MOT results to 2025
Royal Alloy GT 125I vs Piaggio Vespa
The Royal Alloy GT 125I passes its MOT first time more often than the Piaggio Vespa: 84.4% vs 80.7%, a 3.7-point lead.
MOT reliability, side by side
| Metric | Royal Alloy GT 125I | Piaggio Vespa |
|---|---|---|
| First-time pass rate | 84.4% | 80.7% |
| Outright fail rate | 10.6% | 12.2% |
| Vs comparable bikes (age & mileage adjusted) | +6.1 pts | +5.9 pts |
| Engine size | 125cc | 124cc |
| Rank among all models | #2639 of 5428 | #3439 of 5428 |
| Median miles at test | 2,625 | 10,023 |
| MOT tests analysed | 3,329 | 287,482 |
| 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.
What fails, side by side
| Component | Royal Alloy GT 125I | Piaggio Vespa |
|---|---|---|
| Lights & signalling | 4.3% | 6.4% |
| Steering & suspension | 4.7% | 3.2% |
| Brakes | 2.7% | 3.5% |
| Tyres & wheels | 2.2% | 3.8% |
| Structure & body | 1.0% | 1.4% |
| Fuel & exhaust | 0% | 1.3% |
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
| Test year | Royal Alloy GT 125I | Piaggio Vespa |
|---|---|---|
| 2021 | 82.5% | 85.8% |
| 2022 | 83.5% | 86.6% |
| 2023 | 82.4% | 86.5% |
| 2024 | 86.6% | 87.2% |
| 2025 | 85.6% | 87.4% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | Royal Alloy GT 125I | Piaggio Vespa |
|---|---|---|
| 0k-10k miles | 85.1% | 85.0% |
| 10k-20k miles | 71.6% | 77.0% |
Bands with fewer than 30 tests for either bike are left out.
Royal Alloy GT 125I vs Piaggio Vespa FAQ
Which is more reliable, the Royal Alloy GT 125I or the Piaggio Vespa?
The Royal Alloy GT 125I passes its MOT first time more often than the Piaggio Vespa: 84.4% vs 80.7%, a 3.7-point lead. Adjusted for age, mileage and test class the two are level (+6.1 vs +5.9 points against comparable bikes), so the raw gap is mostly down to how old and how used each fleet is. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the Royal Alloy GT 125I fail its MOT on most?
Steering & suspension: 4.7% of Royal Alloy GT 125I MOT tests failed on it, then lights & signalling (4.3%).
What does the Piaggio Vespa fail its MOT on most?
Lights & signalling: 6.4% of Piaggio Vespa MOT tests failed on it, then tyres & wheels (3.8%).
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.