Bsa B31 MOT Pass Rate
Overall pass rate across all manufacture years, based on 104 real MOT test results. Failure rate: 6.7%.
Data from official DVSA MOT testing records
Bsa B31 MOT Reliability Overview
The Bsa B31 is a rare vehicle in the UK, with 104 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 93.3% and a failure rate of 6.7%, which is well above the UK average of approximately 37%.
Based on this data, the Bsa B31 earns a "Excellent" reliability rating. The average Bsa B31 presents for MOT with approximately 17,415 miles on the clock.
The most common MOT failure for the Bsa B31 is Motorcycle brakes, affecting 4.8% of all tests. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. The second most common issue is Motorcycle steering and suspension at 3.8%. Motorcycle body and structure rounds out the top three at 1.0%. Together, these top 3 failure categories account for a significant portion of all MOT failures for this model.
Top failures across all manufacture years combined. Individual year pages may show different top failures.
What Fails Most
* High Fail Rate badge indicates an MOT pass rate below 65% (failure rate above 35%).
What Fails on This Car?
Click a category to see specific failure items.
View as table
| Rank | Failure Category | Rate (%) | Count |
|---|---|---|---|
| 1 | Motorcycle Brakes | 4.8% | 5 |
| 2 | Motorcycle Steering And Suspension | 4.8% | 5 |
| 3 | Motorcycle Body And Structure | 1.0% | 1 |
| 4 | Motorcycle Fuel And Exhaust | 1.0% | 1 |
| 5 | Motorcycle Lighting And Signalling | 1.0% | 1 |
| 6 | Motorcycle Lamps And Reflectors | 1.0% | 1 |
Failures per 10,000 Miles
avg. 17,415 miFor every 10,000 miles driven, this shows what percentage of MOT tests fail for each category. This accounts for how far cars are actually driven, not just raw pass/fail counts.
View as table
| Category | Rate / 10K mi | Raw % | Count |
|---|---|---|---|
| Motorcycle brakes | 2.76 | 4.8% | 5 |
| Motorcycle steering and suspension | 2.76 | 4.8% | 5 |
| Motorcycle body and structure | 0.55 | 1.0% | 1 |
| Motorcycle fuel and exhaust | 0.55 | 1.0% | 1 |
| Motorcycle lighting and signalling | 0.55 | 1.0% | 1 |
| Motorcycle lamps and reflectors | 0.55 | 1.0% | 1 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Bsa B31 has 17,415 miles when tested for MOT.
📊 Mileage-Adjusted Failure Rate
How often this car fails MOT relative to how much it's driven — a fairer comparison than raw pass rate.
The Bsa B31 has a mileage-adjusted failure rate of 3.85% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Bsa B31 MOT Data
The Bsa B31 is a rare vehicle in the UK, with 104 MOT test results recorded in our database spanning 0 manufacture years. It has an overall MOT pass rate of 93.3% and a failure rate of 6.7%, which is well above the UK average of approximately 37%.
For Bsa B31 owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on motorcycle brakes and motorcycle steering and suspension for the best chance of a first-time pass. Use our detailed year-by-year breakdown and failure analysis below to understand how your specific B31 is likely to perform.
Motorcycle brakes — 4.8% of failures
Motorcycle brakes issues account for 4.8% of MOT failures on the Bsa B31. Brake-related failures include worn brake pads, corroded brake discs, leaking brake lines, and faulty brake servos. These are safety-critical components — any brake deficiency will result in an MOT fail. Typical repair costs: £150–400. Pre-MOT check: Listen for squealing or grinding noises. Check brake pedal feel — if it feels spongy or goes to the floor, have the system inspected immediately. Look at brake pad thickness through the wheel spokes (minimum 3mm).
Motorcycle steering and suspension — 3.8% of failures
Motorcycle steering and suspension issues account for 3.8% of MOT failures on the Bsa B31. Suspension failures typically involve worn bushes, leaking shock absorbers, broken coil springs, and damaged suspension arms. These affect ride quality, tyre wear, and road holding. Typical repair costs: £200–500. Pre-MOT check: Look for uneven tyre wear, listen for clunking over bumps, and check if the car pulls to one side. A bouncy ride suggests worn shock absorbers. Visually inspect coil springs for cracks.
Motorcycle body and structure — 1.0% of failures
Motorcycle body and structure issues account for 1.0% of MOT failures on the Bsa B31. Body and structure failures include excessive corrosion, sharp edges, loose panels, and damage to the vehicle frame. Rust is the primary concern, especially on older vehicles or those exposed to road salt. Typical repair costs: £100–500+. Pre-MOT check: Inspect sills, wheel arches, door bottoms, and the chassis for rust. Surface rust is acceptable but structural corrosion or holes will fail. Check that all doors, bonnet, and boot close securely.
Frequently Asked Questions
What is the MOT pass rate for the Bsa B31?
Based on 104 MOT tests in our database, the Bsa B31 has an overall pass rate of 93.3% (6.7% fail rate).
What are the most common MOT failures on a Bsa B31?
The top 3 reasons a Bsa B31 fails its MOT are: 1. Motorcycle brakes (4.8%), 2. Motorcycle steering and suspension (3.8%), 3. Motorcycle body and structure (1.0%). Check these areas before booking your MOT.
Is the Bsa B31 reliable?
With a 6.7% MOT failure rate, the B31 is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Bsa B31?
Based on failure data, focus on: Motorcycle brakes (4.8%); Motorcycle steering and suspension (3.8%); Motorcycle body and structure (1.0%). These are the areas most likely to cause a fail. Also check all lights, tyres (minimum 1.6mm tread), and windscreen condition — these are quick wins that apply to all cars.
Based on DVSA anonymised MOT test data (2005–2024). Crown copyright, Open Government Licence v3.0.