Triumph Twenty One MOT Pass Rate
Overall pass rate across all manufacture years, based on 468 real MOT test results. Failure rate: 7.5%.
Data from official DVSA MOT testing records
Triumph Twenty One MOT Reliability Overview
The Triumph Twenty One is a rare vehicle in the UK, with 468 MOT test results recorded in our database spanning 6 manufacture years. It has an overall MOT pass rate of 92.5% and a failure rate of 7.5%, which is well above the UK average of approximately 37%.
Based on this data, the Triumph Twenty One earns a "Excellent" reliability rating. The average Triumph Twenty One presents for MOT with approximately 22,509 miles on the clock. Manufacture year matters: 1960 models achieve the highest pass rate at 98.3%, while 1961 models have the lowest at 89.4%. This 8.9 percentage point difference suggests notable variation in build quality or component durability across production years.
The most common MOT failure for the Triumph Twenty One is Motorcycle lighting and signalling, affecting 4.1% 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 brakes at 3.8%. Motorcycle steering and suspension rounds out the top three at 2.6%. 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 | 4.3% | 20 |
| 2 | Motorcycle Brakes | 4.1% | 19 |
| 3 | Motorcycle Steering And Suspension | 3.0% | 14 |
| 4 | Motorcycle Tyres And Wheels | 1.7% | 8 |
| 5 | Motorcycle Structure And Attachments | 1.3% | 6 |
| 6 | Motorcycle Tyres | 0.9% | 4 |
| 7 | Motorcycle Steering | 0.6% | 3 |
| 8 | Motorcycle Driving Controls | 0.6% | 3 |
| 9 | Motorcycle Lamps And Reflectors | 0.4% | 2 |
| 10 | Motorcycle Drive System | 0.4% | 2 |
| 11 | Motorcycle Fuel And Exhaust | 0.2% | 1 |
| 12 | Non-component Advisories | 0.2% | 1 |
Failures per 10,000 Miles
avg. 22,509 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 | 1.90 | 4.3% | 20 |
| Motorcycle brakes | 1.80 | 4.1% | 19 |
| Motorcycle steering and suspension | 1.33 | 3.0% | 14 |
| Motorcycle tyres and wheels | 0.76 | 1.7% | 8 |
| Motorcycle structure and attachments | 0.57 | 1.3% | 6 |
| Motorcycle tyres | 0.38 | 0.9% | 4 |
| Motorcycle steering | 0.28 | 0.6% | 3 |
| Motorcycle driving controls | 0.28 | 0.6% | 3 |
| Motorcycle lamps and reflectors | 0.19 | 0.4% | 2 |
| Motorcycle drive system | 0.19 | 0.4% | 2 |
| Motorcycle fuel and exhaust | 0.09 | 0.2% | 1 |
| Non-component advisories | 0.09 | 0.2% | 1 |
🚗 Similar Cars to Consider
Mileage at MOT
The average Triumph Twenty One has 22,509 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 Triumph Twenty One has a mileage-adjusted failure rate of 3.33% per 10,000 miles driven. The average across all makes is 5.38%, so this model is better than average.
About Triumph Twenty One MOT Data
The Triumph Twenty One is a rare vehicle in the UK, with 468 MOT test results recorded in our database spanning 6 manufacture years. It has an overall MOT pass rate of 92.5% and a failure rate of 7.5%, which is well above the UK average of approximately 37%.
For Triumph Twenty One 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 brakes 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 Twenty One is likely to perform.
Motorcycle lighting and signalling — 4.1% of failures
Motorcycle lighting and signalling issues account for 4.1% of MOT failures on the Triumph Twenty One. 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 brakes — 3.8% of failures
Motorcycle brakes issues account for 3.8% of MOT failures on the Triumph Twenty One. 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 — 2.6% of failures
Motorcycle steering and suspension issues account for 2.6% of MOT failures on the Triumph Twenty One. 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.
Frequently Asked Questions
What is the MOT pass rate for the Triumph Twenty One?
Based on 468 MOT tests in our database, the Triumph Twenty One has an overall pass rate of 92.5% (7.5% fail rate).
What are the most common MOT failures on a Triumph Twenty One?
The top 3 reasons a Triumph Twenty One fails its MOT are: 1. Motorcycle lighting and signalling (4.1%), 2. Motorcycle brakes (3.8%), 3. Motorcycle steering and suspension (2.6%). Check these areas before booking your MOT.
Is the Triumph Twenty One reliable?
With a 7.5% MOT failure rate, the Twenty One is more reliable than average compared to the UK average of ~40%.
What should I check before an MOT on my Triumph Twenty One?
Based on failure data, focus on: Motorcycle lighting and signalling (4.1%); Motorcycle brakes (3.8%); Motorcycle steering and suspension (2.6%). 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.