Norton 99 MOT Pass Rate
Overall pass rate across all manufacture years, based on 254 real MOT test results. Failure rate: 4.7%.
Data from official DVSA MOT testing records
Norton 99 MOT Reliability Overview
The Norton 99 is a rare vehicle in the UK, with 254 MOT test results recorded in our database spanning 3 manufacture years. It has an overall MOT pass rate of 95.3% and a failure rate of 4.7%, which is well above the UK average of approximately 37%.
Based on this data, the Norton 99 earns a "Excellent" reliability rating. The average Norton 99 presents for MOT with approximately 22,508 miles on the clock. Manufacture year matters: 1961 models achieve the highest pass rate at 96.3%, while 1962 models have the lowest at 86.5%. This 9.8 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Norton 99 is Motorcycle lighting and signalling, affecting 3.1% of all tests. 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. The second most common issue is Motorcycle steering and suspension at 2.4%. Motorcycle drive system rounds out the top three at 0.8%. 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 Lighting And Signalling | 3.1% | 8 |
| 2 | Motorcycle Steering And Suspension | 2.8% | 7 |
| 3 | Motorcycle Drive System | 0.8% | 2 |
| 4 | Motorcycle Brakes | 0.4% | 1 |
| 5 | Motorcycle Driving Controls | 0.4% | 1 |
| 6 | Motorcycle Tyres And Wheels | 0.4% | 1 |
| 7 | Motorcycle Lamps And Reflectors | 0.4% | 1 |
| 8 | Motorcycle Tyres | 0.4% | 1 |
Failures per 10,000 Miles
avg. 22,508 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 lighting and signalling | 1.40 | 3.1% | 8 |
| Motorcycle steering and suspension | 1.22 | 2.8% | 7 |
| Motorcycle drive system | 0.35 | 0.8% | 2 |
| Motorcycle brakes | 0.17 | 0.4% | 1 |
| Motorcycle driving controls | 0.17 | 0.4% | 1 |
| Motorcycle tyres and wheels | 0.17 | 0.4% | 1 |
| Motorcycle lamps and reflectors | 0.17 | 0.4% | 1 |
| Motorcycle tyres | 0.17 | 0.4% | 1 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Norton 99 has 22,508 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 Norton 99 has a mileage-adjusted failure rate of 2.09% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Norton 99 MOT Data
The Norton 99 is a rare vehicle in the UK, with 254 MOT test results recorded in our database spanning 3 manufacture years. It has an overall MOT pass rate of 95.3% and a failure rate of 4.7%, which is well above the UK average of approximately 37%.
For Norton 99 owners, these results suggest a reliable vehicle that generally passes its MOT without major issues. Focus your pre-MOT checks on motorcycle lighting and signalling 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 99 is likely to perform.
Motorcycle lighting and signalling — 3.1% of failures
Motorcycle lighting and signalling issues account for 3.1% of MOT failures on the Norton 99. 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 steering and suspension — 2.4% of failures
Motorcycle steering and suspension issues account for 2.4% of MOT failures on the Norton 99. 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 drive system — 0.8% of failures
Motorcycle drive system issues account for 0.8% of MOT failures on the Norton 99. Motorcycle drive system 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 Norton 99?
Based on 254 MOT tests in our database, the Norton 99 has an overall pass rate of 95.3% (4.7% fail rate).
What are the most common MOT failures on a Norton 99?
The top 3 reasons a Norton 99 fails its MOT are: 1. Motorcycle lighting and signalling (3.1%), 2. Motorcycle steering and suspension (2.4%), 3. Motorcycle drive system (0.8%). Check these areas before booking your MOT.
Is the Norton 99 reliable?
With a 4.7% MOT failure rate, the 99 is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Norton 99?
Based on failure data, focus on: Motorcycle lighting and signalling (3.1%); Motorcycle steering and suspension (2.4%); Motorcycle drive system (0.8%). 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.