Norton 18
Real ownership data from 157 UK 18 motorcycles — mileage, MOT pass rates and the faults that actually come up, taken from DVSA test records rather than opinion.
Most common 18 problems
Ranked by how often each fault appears in this model's MOT history.
| Fault | Severity | Share of faults |
|---|---|---|
| Other | fail | 39.2% |
| Lights and indicators | major | 7.3% |
| Brakes | fail | 5.2% |
| Tyres | major | 3% |
| Steering and head bearings | fail | 2.2% |
| Wheels | fail | 1.7% |
| Electrical | major | 1.7% |
| Suspension | fail | 1.3% |
Advisories (wear noted but not failed) are excluded above; the most common is suspension.
18 mileage and reliability by year
Use this to judge whether a specific bike is high or low mileage for its age.
| Year | Examples | Median mileage | Miles/year | First-time pass |
|---|---|---|---|---|
| 1949 | 5 | 13,627 mi | 672 | 100% |
| 1948 | 7 | 26,561 mi | 278 | 92.59% |
| 1947 | 7 | 24,401 mi | 516 | 92% |
| 1946 | 12 | 2,140 mi | 331 | 96.77% |
| 1934 | 5 | 2,496 mi | 800 | 100% |
| 1933 | 5 | 340 mi | 72 | 100% |
| 1929 | 5 | — | — | 100% |
| 1928 | 5 | 1 mi | — | 100% |
| 1926 | 6 | — | — | 100% |
18 questions, answered with data
What are the most common problems with the Norton 18?
Across 157 UK examples, the most frequently recorded MOT faults are other (39.2% of all recorded faults), lights and indicators (7.3% of all recorded faults), brakes (5.2% of all recorded faults).
What is average mileage for a Norton 18?
The median Norton 18 in the UK has covered 6,082 miles, and typically rides about 305 miles a year. Half of all examples fall between 1,172 and 20,572 miles.
Is the Norton 18 reliable?
95.45% of Norton 18 MOT tests are passed first time, with an average of 0.41 faults recorded per test. This is measured from DVSA MOT records, not owner opinion.
Based on DVSA MOT test records for 157 Norton 18 motorcycles registered in Great Britain and Northern Ireland. Contains public sector information licensed under the Open Government Licence v3.0.