BSA B31
Real ownership data from 924 UK B31 motorcycles — mileage, MOT pass rates and the faults that actually come up, taken from DVSA test records rather than opinion.
Most common B31 problems
Ranked by how often each fault appears in this model's MOT history.
| Fault | Severity | Share of faults |
|---|---|---|
| Brakes | fail | 9.3% |
| Lights and indicators | fail | 9.1% |
| Other | fail | 7.5% |
| Tyres | fail | 4.6% |
| Fluid leaks | fail | 3% |
| Electrical | fail | 2.7% |
| Steering and head bearings | fail | 2.5% |
| Suspension | fail | 2.3% |
Advisories (wear noted but not failed) are excluded above; the most common is suspension.
B31 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 |
|---|---|---|---|---|
| 2012 | 12 | 5,986 mi | — | 84.62% |
| 2011 | 5 | 2,976 mi | 74 | 77.78% |
| 2010 | 13 | 2,859 mi | 317 | 82.76% |
| 2009 | 5 | 7,073 mi | 518 | 90% |
| 2008 | 7 | 2,835 mi | 506 | 89.29% |
| 2006 | 8 | 18,888 mi | 266 | 90.63% |
| 2005 | 5 | 4,850 mi | 1,982 | 81.82% |
| 2004 | 8 | 18,569 mi | 67 | 97.22% |
| 2003 | 11 | 5,721 mi | 86 | 93.62% |
| 2002 | 11 | 7,726 mi | 474 | 93.55% |
| 2001 | 6 | 32,320 mi | 4 | 87.5% |
| 2000 | 11 | 1,291 mi | 60 | 94.12% |
| 1997 | 11 | 18,779 mi | 52 | 89.13% |
| 1996 | 12 | 6,551 mi | 386 | 90% |
| 1995 | 5 | 12,655 mi | 379 | 95.24% |
| 1994 | 7 | 12,392 mi | 36 | 96.77% |
| 1993 | 5 | 1,329 mi | 24 | 100% |
| 1992 | 6 | 7,249 mi | 244 | 96.3% |
| 1991 | 11 | 10,386 mi | 617 | 98.36% |
| 1990 | 11 | 22,365 mi | 73 | 82.93% |
B31 questions, answered with data
What are the most common problems with the BSA B31?
Across 924 UK examples, the most frequently recorded MOT faults are brakes (9.3% of all recorded faults), lights and indicators (9.1% of all recorded faults), other (7.5% of all recorded faults).
What is average mileage for a BSA B31?
The median BSA B31 in the UK has covered 14,160 miles, and typically rides about 178 miles a year. Half of all examples fall between 2,922 and 38,737 miles.
Is the BSA B31 reliable?
92.15% of BSA B31 MOT tests are passed first time, with an average of 0.44 faults recorded per test. This is measured from DVSA MOT records, not owner opinion.
Based on DVSA MOT test records for 924 BSA B31 motorcycles registered in Great Britain and Northern Ireland. Contains public sector information licensed under the Open Government Licence v3.0.