Data as of: DVSA MOT results to 2025
Derbi GPR50-R vs Piaggio Zip
The Piaggio Zip passes its MOT first time more often than the Derbi GPR50-R: 71.3% vs 53.4%, a 17.9-point lead.
MOT reliability, side by side
| Metric | Derbi GPR50-R | Piaggio Zip |
|---|---|---|
| First-time pass rate | 53.4% | 71.3% |
| Outright fail rate | 37.2% | 20.4% |
| Vs comparable bikes (age & mileage adjusted) | -16.6 pts | -1.0 pts |
| Engine size | 49cc | 49cc |
| Rank among all models | #5356 of 5428 | #4631 of 5428 |
| Median miles at test | 13,707 | 8,882 |
| MOT tests analysed | 1,901 | 78,993 |
| 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
| Component | Derbi GPR50-R | Piaggio Zip |
|---|---|---|
| Lights & signalling | 26.1% | 11.9% |
| Steering & suspension | 23.5% | 9.2% |
| Brakes | 15.4% | 6.5% |
| Drive system | 9.1% | 0.0% |
| Tyres & wheels | 4.6% | 4.0% |
| Structure & body | 6.3% | 1.6% |
| Fuel & exhaust | 3.5% | 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
| Test year | Derbi GPR50-R | Piaggio Zip |
|---|---|---|
| 2011 | 53.4% | 69.7% |
| 2012 | 48.3% | 69.1% |
| 2013 | 49.1% | 69.7% |
| 2014 | 59.3% | 68.8% |
| 2015 | 57.0% | 69.8% |
| 2016 | 64.2% | 71.0% |
| 2017 | 65.8% | 71.7% |
| 2020 | 66.7% | 73.1% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | Derbi GPR50-R | Piaggio Zip |
|---|---|---|
| 0k-10k miles | 57.7% | 75.2% |
| 10k-20k miles | 50.1% | 66.7% |
| 20k-30k miles | 55.6% | 64.4% |
| 30k-40k miles | 50.4% | 64.5% |
Bands with fewer than 30 tests for either bike are left out.
Derbi GPR50-R vs Piaggio Zip FAQ
Which is more reliable, the Derbi GPR50-R or the Piaggio Zip?
The Piaggio Zip passes its MOT first time more often than the Derbi GPR50-R: 71.3% vs 53.4%, a 17.9-point lead. Adjusted for age, mileage and test class, the Piaggio Zip still comes out ahead: -16.6 points vs comparable bikes for the Derbi GPR50-R, -1.0 for the Piaggio Zip. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the Derbi GPR50-R fail its MOT on most?
Lights & signalling: 26.1% of Derbi GPR50-R MOT tests failed on it, then steering & suspension (23.5%).
What does the Piaggio Zip fail its MOT on most?
Lights & signalling: 11.9% of Piaggio Zip MOT tests failed on it, then steering & suspension (9.2%).
Which holds up better at high mileage, the Derbi GPR50-R or the Piaggio Zip?
At 30k-40k miles the Piaggio Zip passes first time more often: 50.4% for the Derbi GPR50-R vs 64.5% for the Piaggio Zip.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.