Data as of: DVSA MOT results to 2025
Triumph Speed Four vs Yamaha FZS600
The Yamaha FZS600 passes its MOT first time more often than the Triumph Speed Four: 82.6% vs 81.4%, a 1.2-point lead.
MOT reliability, side by side
| Metric | Triumph Speed Four | Yamaha FZS600 |
|---|---|---|
| First-time pass rate | 81.4% | 82.6% |
| Outright fail rate | 11.3% | 10.6% |
| Vs comparable bikes (age & mileage adjusted) | -4.0 pts | -0.8 pts |
| Engine size | 599cc | 599cc |
| Rank among all models | #3291 of 5428 | #3052 of 5428 |
| Median miles at test | 14,114 | 21,612 |
| MOT tests analysed | 8,421 | 136,558 |
| Most common failure | lighting and signalling | 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 | Triumph Speed Four | Yamaha FZS600 |
|---|---|---|
| Brakes | 3.8% | 4.5% |
| Lights & signalling | 4.9% | 3.4% |
| Steering & suspension | 3.6% | 2.7% |
| Tyres & wheels | 2.2% | 2.9% |
| Structure & body | 1.2% | 1.1% |
| Drive system | 1.0% | 0.9% |
| Fuel & exhaust | 0.3% | 1.1% |
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 | Triumph Speed Four | Yamaha FZS600 |
|---|---|---|
| 2018 | 81.7% | 81.3% |
| 2019 | 78.5% | 83.0% |
| 2020 | 79.4% | 83.6% |
| 2021 | 81.0% | 82.8% |
| 2022 | 81.6% | 83.6% |
| 2023 | 78.0% | 84.2% |
| 2024 | 80.8% | 83.3% |
| 2025 | 85.6% | 84.0% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | Triumph Speed Four | Yamaha FZS600 |
|---|---|---|
| 0k-10k miles | 87.3% | 89.6% |
| 10k-20k miles | 81.0% | 85.5% |
| 20k-30k miles | 76.3% | 81.4% |
| 30k-40k miles | 75.9% | 78.7% |
| 40k-50k miles | 65.5% | 76.8% |
| 50k-60k miles | 80.0% | 74.7% |
Bands with fewer than 30 tests for either bike are left out.
Triumph Speed Four vs Yamaha FZS600 FAQ
Which is more reliable, the Triumph Speed Four or the Yamaha FZS600?
The Yamaha FZS600 passes its MOT first time more often than the Triumph Speed Four: 82.6% vs 81.4%, a 1.2-point lead. Adjusted for age, mileage and test class, the Yamaha FZS600 still comes out ahead: -4.0 points vs comparable bikes for the Triumph Speed Four, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the Triumph Speed Four fail its MOT on most?
Lights & signalling: 4.9% of Triumph Speed Four MOT tests failed on it, then brakes (3.8%).
What does the Yamaha FZS600 fail its MOT on most?
Brakes: 4.5% of Yamaha FZS600 MOT tests failed on it, then lights & signalling (3.4%).
Which holds up better at high mileage, the Triumph Speed Four or the Yamaha FZS600?
At 50k-60k miles the Triumph Speed Four passes first time more often: 80.0% for the Triumph Speed Four vs 74.7% for the Yamaha FZS600.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.