Data as of: DVSA MOT results to 2025
Honda CB400 vs Honda CB500
The Honda CB500 passes its MOT first time more often than the Honda CB400: 83.3% vs 80.9%, a 2.4-point lead.
MOT reliability, side by side
| Metric | Honda CB400 | Honda CB500 |
|---|---|---|
| First-time pass rate | 80.9% | 83.3% |
| Outright fail rate | 11.0% | 10.1% |
| Vs comparable bikes (age & mileage adjusted) | -1.6 pts | -0.8 pts |
| Engine size | 400cc | 499cc |
| Rank among all models | #3398 of 5428 | #2895 of 5428 |
| Median miles at test | 30,796 | 20,653 |
| MOT tests analysed | 9,072 | 104,748 |
| Most common failure | steering and suspension | 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 | Honda CB400 | Honda CB500 |
|---|---|---|
| Steering & suspension | 4.9% | 4.2% |
| Brakes | 4.0% | 4.2% |
| Lights & signalling | 4.5% | 3.4% |
| Tyres & wheels | 2.3% | 2.3% |
| Drive system | 1.1% | 1.0% |
| Structure & body | 0.6% | 1.1% |
| Fuel & exhaust | 0.6% | 0.4% |
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 | Honda CB400 | Honda CB500 |
|---|---|---|
| 2018 | 86.0% | 84.0% |
| 2019 | 86.7% | 85.7% |
| 2020 | 87.6% | 89.1% |
| 2021 | 86.7% | 89.0% |
| 2022 | 85.8% | 89.1% |
| 2023 | 90.4% | 89.5% |
| 2024 | 79.1% | 90.1% |
| 2025 | 86.4% | 90.3% |
Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.
Pass rate by mileage
| Mileage | Honda CB400 | Honda CB500 |
|---|---|---|
| 0k-10k miles | 80.9% | 92.5% |
| 10k-20k miles | 83.0% | 86.3% |
| 20k-30k miles | 83.3% | 80.5% |
| 30k-40k miles | 81.6% | 77.6% |
| 40k-50k miles | 80.9% | 74.9% |
| 50k-60k miles | 75.0% | 74.6% |
Bands with fewer than 30 tests for either bike are left out.
Honda CB400 vs Honda CB500 FAQ
Which is more reliable, the Honda CB400 or the Honda CB500?
The Honda CB500 passes its MOT first time more often than the Honda CB400: 83.3% vs 80.9%, a 2.4-point lead. Adjusted for age, mileage and test class the two are level (-1.6 vs -0.8 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 Honda CB400 fail its MOT on most?
Steering & suspension: 4.9% of Honda CB400 MOT tests failed on it, then lights & signalling (4.5%).
What does the Honda CB500 fail its MOT on most?
Steering & suspension: 4.2% of Honda CB500 MOT tests failed on it, then brakes (4.2%).
Which holds up better at high mileage, the Honda CB400 or the Honda CB500?
They are level: at 50k-60k miles the Honda CB400 passes 75.0% first time and the Honda CB500 74.6%.
See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.