Bsa M21 MOT Pass Rate
Overall pass rate across all manufacture years, based on 189 real MOT test results. Failure rate: 6.9%.
Data from official DVSA MOT testing records
Bsa M21 MOT Reliability Overview
The Bsa M21 is a rare vehicle in the UK, with 189 MOT test results recorded in our database spanning 2 manufacture years. It has an overall MOT pass rate of 93.1% and a failure rate of 6.9%, which is well above the UK average of approximately 37%.
Based on this data, the Bsa M21 earns a "Excellent" reliability rating. The average Bsa M21 presents for MOT with approximately 32,230 miles on the clock. Manufacture year matters: 1961 models achieve the highest pass rate at 94.7%, while 1960 models have the lowest at 91.8%. This 2.9 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Bsa M21 is Motorcycle steering and suspension, affecting 3.7% of all tests. 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. The second most common issue is Motorcycle lighting and signalling at 3.2%. Motorcycle fuel and exhaust rounds out the top three at 2.1%. 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
Pass Rate by Manufacture Year
* 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 Steering And Suspension | 4.2% | 8 |
| 2 | Motorcycle Lighting And Signalling | 3.2% | 6 |
| 3 | Motorcycle Tyres And Wheels | 2.6% | 5 |
| 4 | Motorcycle Fuel And Exhaust | 2.1% | 4 |
| 5 | Motorcycle Drive System | 1.6% | 3 |
| 6 | Motorcycle Body And Structure | 1.1% | 2 |
| 7 | Motorcycle Driving Controls | 0.5% | 1 |
| 8 | Motorcycle Brakes | 0.5% | 1 |
| 9 | Motorcycle Audible Warning (Horn) | 0.5% | 1 |
Failures per 10,000 Miles
avg. 32,230 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 steering and suspension | 1.31 | 4.2% | 8 |
| Motorcycle lighting and signalling | 0.98 | 3.2% | 6 |
| Motorcycle tyres and wheels | 0.82 | 2.6% | 5 |
| Motorcycle fuel and exhaust | 0.66 | 2.1% | 4 |
| Motorcycle drive system | 0.49 | 1.6% | 3 |
| Motorcycle body and structure | 0.33 | 1.1% | 2 |
| Motorcycle driving controls | 0.16 | 0.5% | 1 |
| Motorcycle brakes | 0.16 | 0.5% | 1 |
| Motorcycle audible warning (Horn) | 0.16 | 0.5% | 1 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Bsa M21 has 32,230 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 M21 has a mileage-adjusted failure rate of 2.14% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Bsa M21 MOT Data
The Bsa M21 is a rare vehicle in the UK, with 189 MOT test results recorded in our database spanning 2 manufacture years. It has an overall MOT pass rate of 93.1% and a failure rate of 6.9%, which is well above the UK average of approximately 37%.
For Bsa M21 owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on motorcycle steering and suspension and motorcycle lighting and signalling 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 M21 is likely to perform.
Motorcycle steering and suspension — 3.7% of failures
Motorcycle steering and suspension issues account for 3.7% of MOT failures on the Bsa M21. 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 lighting and signalling — 3.2% of failures
Motorcycle lighting and signalling issues account for 3.2% of MOT failures on the Bsa M21. Motorcycle lighting and signalling issues are a common cause of MOT failure. Regular inspection and maintenance of these components helps ensure your vehicle passes its MOT. Typical repair costs: £100–400. Pre-MOT check: Have this system checked during regular servicing. Look for warning signs like unusual noises, vibrations, or dashboard warning lights.
Motorcycle fuel and exhaust — 2.1% of failures
Motorcycle fuel and exhaust issues account for 2.1% of MOT failures on the Bsa M21. Motorcycle fuel and exhaust issues are a common cause of MOT failure. Regular inspection and maintenance of these components helps ensure your vehicle passes its MOT. Typical repair costs: £100–400. Pre-MOT check: Have this system checked during regular servicing. Look for warning signs like unusual noises, vibrations, or dashboard warning lights.
Frequently Asked Questions
What is the MOT pass rate for the Bsa M21?
Based on 189 MOT tests in our database, the Bsa M21 has an overall pass rate of 93.1% (6.9% fail rate).
What are the most common MOT failures on a Bsa M21?
The top 3 reasons a Bsa M21 fails its MOT are: 1. Motorcycle steering and suspension (3.7%), 2. Motorcycle lighting and signalling (3.2%), 3. Motorcycle fuel and exhaust (2.1%). Check these areas before booking your MOT.
Is the Bsa M21 reliable?
With a 6.9% MOT failure rate, the M21 is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Bsa M21?
Based on failure data, focus on: Motorcycle steering and suspension (3.7%); Motorcycle lighting and signalling (3.2%); Motorcycle fuel and exhaust (2.1%). 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.