Data as of: DVSA MOT results to 2025
KTM 640 Duke Ii vs Triumph Street Triple
The Triumph Street Triple passes its MOT first time more often than the KTM 640 Duke Ii: 87.7% vs 80.6%, a 7.1-point lead.
MOT reliability, side by side
| Metric | KTM 640 Duke Ii | Triumph Street Triple |
|---|---|---|
| First-time pass rate | 80.6% | 87.7% |
| Outright fail rate | 9.9% | 5.9% |
| Vs comparable bikes (age & mileage adjusted) | -6.5 pts | +1.3 pts |
| Engine size | 625cc | 675cc |
| Rank among all models | #3459 of 5428 | #1695 of 5428 |
| Median miles at test | 8,889 | 11,189 |
| MOT tests analysed | 4,182 | 37,699 |
| 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 | KTM 640 Duke Ii | Triumph Street Triple |
|---|---|---|
| Lights & signalling | 6.0% | 2.6% |
| Steering & suspension | 2.2% | 1.2% |
| Tyres & wheels | 2.2% | 1.2% |
| Brakes | 1.5% | 1.6% |
| Drive system | 1.1% | 0.2% |
| Structure & body | 0.5% | 0.7% |
| Fuel & exhaust | 0.7% | 0.1% |
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 | KTM 640 Duke Ii | Triumph Street Triple |
|---|---|---|
| 2018 | 82.3% | 87.8% |
| 2019 | 80.6% | 87.9% |
| 2020 | 81.2% | 89.6% |
| 2021 | 72.5% | 87.2% |
| 2022 | 83.2% | 87.3% |
| 2023 | 87.8% | 87.5% |
| 2024 | 84.1% | 88.0% |
| 2025 | 84.0% | 86.4% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | KTM 640 Duke Ii | Triumph Street Triple |
|---|---|---|
| 0k-10k miles | 83.3% | 91.3% |
| 10k-20k miles | 78.0% | 86.7% |
| 20k-30k miles | 74.8% | 82.7% |
| 30k-40k miles | 65.1% | 79.9% |
Bands with fewer than 30 tests for either bike are left out.
KTM 640 Duke Ii vs Triumph Street Triple FAQ
Which is more reliable, the KTM 640 Duke Ii or the Triumph Street Triple?
The Triumph Street Triple passes its MOT first time more often than the KTM 640 Duke Ii: 87.7% vs 80.6%, a 7.1-point lead. Adjusted for age, mileage and test class, the Triumph Street Triple still comes out ahead: -6.5 points vs comparable bikes for the KTM 640 Duke Ii, +1.3 for the Triumph Street Triple. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the KTM 640 Duke Ii fail its MOT on most?
Lights & signalling: 6.0% of KTM 640 Duke Ii MOT tests failed on it, then steering & suspension (2.2%).
What does the Triumph Street Triple fail its MOT on most?
Lights & signalling: 2.6% of Triumph Street Triple MOT tests failed on it, then brakes (1.6%).
Which holds up better at high mileage, the KTM 640 Duke Ii or the Triumph Street Triple?
At 30k-40k miles the Triumph Street Triple passes first time more often: 65.1% for the KTM 640 Duke Ii vs 79.9% for the Triumph Street Triple.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.