Data as of: DVSA MOT results to 2025
Sinnis Terrain 125 vs Yamaha YBR 125
The Sinnis Terrain 125 passes its MOT first time more often than the Yamaha YBR 125: 74.1% vs 71.0%, a 3.1-point lead.
MOT reliability, side by side
| Metric | Sinnis Terrain 125 | Yamaha YBR 125 |
|---|---|---|
| First-time pass rate | 74.1% | 71.0% |
| Outright fail rate | 19.7% | 17.1% |
| Vs comparable bikes (age & mileage adjusted) | -1.8 pts | -1.1 pts |
| Engine size | 125cc | 124cc |
| Rank among all models | #4387 of 5428 | #4664 of 5428 |
| Median miles at test | 5,614 | 10,652 |
| MOT tests analysed | 660 | 124,897 |
| Most common failure | brakes | brakes |
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 | Sinnis Terrain 125 | Yamaha YBR 125 |
|---|---|---|
| Lights & signalling | 8.0% | 8.5% |
| Brakes | 8.5% | 5.9% |
| Steering & suspension | 7.6% | 6.5% |
| Structure & body | 8.0% | 3.8% |
| Tyres & wheels | 3.9% | 4.4% |
| Drive system | 0% | 2.9% |
| Fuel & exhaust | 0% | 0.6% |
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 mileage
| Mileage | Sinnis Terrain 125 | Yamaha YBR 125 |
|---|---|---|
| 0k-10k miles | 78.0% | 76.8% |
| 10k-20k miles | 58.4% | 67.4% |
Bands with fewer than 30 tests for either bike are left out.
Sinnis Terrain 125 vs Yamaha YBR 125 FAQ
Which is more reliable, the Sinnis Terrain 125 or the Yamaha YBR 125?
The Sinnis Terrain 125 passes its MOT first time more often than the Yamaha YBR 125: 74.1% vs 71.0%, a 3.1-point lead. Adjusted for age, mileage and test class the two are level (-1.8 vs -1.1 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 Sinnis Terrain 125 fail its MOT on most?
Brakes: 8.5% of Sinnis Terrain 125 MOT tests failed on it, then lights & signalling (8.0%).
What does the Yamaha YBR 125 fail its MOT on most?
Lights & signalling: 8.5% of Yamaha YBR 125 MOT tests failed on it, then steering & suspension (6.5%).
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.