KTM 390 DUKE 21 MOT pass rate and common failures
KTM 390 DUKE 21 motorcycles pass the MOT 86.67% of the time, measured across 255 tests in the DVSA record. A further 5.1% passed only after a defect was put right at the test station.
What to check before the MOT
Built from this model's own failure record, not general advice.
- Start with missing - it accounts for 81% of failed tests on this model.
- Then check too high and has negligible damping effect, the next two most common reasons.
- The most common advisory is noise is clearly in excess of that emitted by a similar motorcycle fitted with a standard silencer in average condition (4.7% of all tests) - not a failure, but money you will spend sooner or later.
- Average recorded mileage at test is 5,497 miles, which is the number to compare any advert against.
Pass rate by age
A single pass rate hides the most useful thing in this data: how the same model behaves at three years old and at fifteen.
| Age at test | Pass rate | Tests | |
|---|---|---|---|
| 3-5 years | 86.67% | 255 |
Why the KTM 390 DUKE 21 fails
Share of failed tests on this model where the item was recorded. One test can fail on several items, so the column does not add up to 100%.
| # | Item | Of failures | Tests | |
|---|---|---|---|---|
| 1 | Missing | 81% | 17 | |
| 2 | Too high | 19% | 4 | |
| 3 | Has negligible damping effect | 14.3% | 3 | |
| 4 | Less than 1.0 mm thick | 14.3% | 3 | |
| 5 | Tread depth is below minimum requirements of 1.0mm | 14.3% | 3 | |
| 6 | Does not conform to the specified requirements | 9.5% | 2 | |
| 7 | Excessively loose | 9.5% | 2 | |
| 8 | Has a serious fluid leak | 9.5% | 2 | |
| 9 | Has excessive play | 9.5% | 2 | |
| 10 | Has excessive wear or free play | 9.5% | 2 |
Most common advisories
Not a failure and not a legal requirement to fix - but an advisory that repeats year after year is money the next owner spends.
| # | Item | Of all tests | Tests | |
|---|---|---|---|---|
| 1 | Noise is clearly in excess of that emitted by a similar motorcycle fitted with a standard silencer in average condition | 4.7% | 12 | |
| 2 | Tread depth is below minimum requirements of 1.0mm | 4.3% | 11 | |
| 3 | Indicates excessive fluctuation of brake effort | 3.1% | 8 | |
| 4 | Excessively loose | 2.4% | 6 | |
| 5 | Worn to excess | 2% | 5 | |
| 6 | Excessively binding | 1.6% | 4 | |
| 7 | Has a serious fluid leak | 1.6% | 4 | |
| 8 | Inscription illegible | 1.6% | 4 | |
| 9 | Tread not clearly visible | 1.6% | 4 | |
| 10 | Excessively tight | 0.8% | 2 |
KTM 390 DUKE 21 for sale
No KTM 390 DUKE 21 in stock at the moment - 297 other KTM bikes are advertised.
Similar bikes compared
Models of comparable capacity, so the comparison means something.
| Model | Tests | Pass rate | Avg mileage | |
|---|---|---|---|---|
| Piaggio VESPA GTS · 240-300cc | 4,305 | 92.15% | 9,875 | |
| Royal Enfield HIMALAYAN · 411cc | 2,371 | 88.49% | 8,163 | |
| Royal Enfield METEOR 350 · 349cc | 2,133 | 93.95% | 4,543 | |
| Honda NSS 250-297cc · 250-297cc | 1,397 | 90.34% | 17,407 | |
| Honda CRF 300 LA-M · 286cc | 1,297 | 88.43% | 3,963 | |
| BMW G310 · 313cc | 1,129 | 90.79% | 7,243 |
Source: DVSA MOT testing data, 2025 · updated Aug 2026 · licence and method