Data as of: DVSA MOT results to 2025
KTM 390 Duke 18 vs Honda CB400
The KTM 390 Duke 18 passes its MOT first time more often than the Honda CB400: 89.5% vs 80.9%, a 8.6-point lead.
MOT reliability, side by side
| Metric | KTM 390 Duke 18 | Honda CB400 |
|---|---|---|
| First-time pass rate | 89.5% | 80.9% |
| Outright fail rate | 4.8% | 11.0% |
| Vs comparable bikes (age & mileage adjusted) | +0.4 pts | -1.6 pts |
| Engine size | 373cc | 400cc |
| Rank among all models | #1113 of 5428 | #3398 of 5428 |
| Median miles at test | 4,582 | 30,796 |
| MOT tests analysed | 1,030 | 9,072 |
| Most common failure | lamps and reflectors | steering and suspension |
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 390 Duke 18 | Honda CB400 |
|---|---|---|
| Lights & signalling | 1.9% | 4.5% |
| Steering & suspension | 1.0% | 4.9% |
| Brakes | 1.6% | 4.0% |
| Tyres & wheels | 1.2% | 2.3% |
| Structure & body | 1.3% | 0.6% |
| Drive system | 0% | 1.1% |
| 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 test year
| Test year | KTM 390 Duke 18 | Honda CB400 |
|---|---|---|
| 2021 | 86.2% | 86.7% |
| 2022 | 91.6% | 85.8% |
| 2023 | 88.0% | 90.4% |
| 2024 | 91.2% | 79.1% |
| 2025 | 90.6% | 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 390 Duke 18 | Honda CB400 |
|---|---|---|
| 0k-10k miles | 89.7% | 80.9% |
| 10k-20k miles | 88.7% | 83.0% |
Bands with fewer than 30 tests for either bike are left out.
KTM 390 Duke 18 vs Honda CB400 FAQ
Which is more reliable, the KTM 390 Duke 18 or the Honda CB400?
The KTM 390 Duke 18 passes its MOT first time more often than the Honda CB400: 89.5% vs 80.9%, a 8.6-point lead. Adjusted for age, mileage and test class, the KTM 390 Duke 18 still comes out ahead: +0.4 points vs comparable bikes for the KTM 390 Duke 18, -1.6 for the Honda CB400. An MOT checks roadworthiness items, not engine or gearbox internals.
What does the KTM 390 Duke 18 fail its MOT on most?
Lights & signalling: 1.9% of KTM 390 Duke 18 MOT tests failed on it, then brakes (1.6%).
What does the Honda CB400 fail its MOT on most?
Steering & suspension: 4.9% of Honda CB400 MOT tests failed on it, then lights & signalling (4.5%).
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.