| Most common failures | No# failures |
|---|
| Headlamp aim out of alignment | 394 |
| Headlamp at least one does not illuminate on dipped beam |1.2.2a|i|| | 247 |
| Drive chain excessively loose |6.2.1d| | 181 |
| Drive chain worn to excess |6.2.1e| | 85 |
| Front Roller brake test indicates a binding brake |3.3.A1a| | 67 |
| Nearside Front shock absorber seal failed and leaking oil |2.3.3| | 60 |
| Rear Drive chain sprocket worn to excess |6.2.1e| | 53 |
| Rear position lamp does not illuminate immediately when it is switched on |1.1.3a| | 51 |
| Rear Stop lamp does not illuminate immediately a brake applies |1.3.1a| | 51 |
| Front position lamp does not illuminate immediately when switched on |1.1.3a| | 48 |
| Headlamp at least one does not illuminate on main beam |1.2.2a|ii|| | 45 |
| Offside Front shock absorber seal failed and leaking oil |2.3.3| | 44 |
| Stop lamp does not illuminate immediately a brake applies |1.3.1a| | 43 |
| Horn not working |1.7.3a| | 43 |
| Registration plate issues | 40 |
| Wheel alignment incorrect which adversely affects the handling |2.5.1| | 39 |
| Steering movement excessively `notchy` with the wheel raised |2.2.1b| | 38 |
| Headlamp not working on dipped beam (4.1.1 (a) (ii)) | 38 |
| Rear reflector on motorcycle missing |1.4.1| | 36 |
| Exhaust is leaking and excessively noisey |7.1.1b| | 33 |
| Front Headlamp at least one does not illuminate on dipped beam |1.2.2a|i|| | 33 |
| Front Stop lamp does not illuminate immediately a brake applies |1.3.1a| | 32 |
| Headlamp insecure |1.2.3b| | 31 |
| Handlebar deformed |2.1.1b| | 30 |
| Drive chain excessively loose (6.1.7 (c) (i)) | 29 |
| Headlamp aim beam image kick up to the offside |1.6| | 27 |
| Rear Roller brake test indicates a binding brake |3.3.A1a| | 26 |
| Steering headbearing has excessive free play |2.2.2| | 26 |
| Steering movement excessively `notchy` with the weight on the lower bearing |2.2.1a| | 26 |
| Stop lamp remains on when the brakes are released | 26 |
| Drive chain excessively tight |6.2.1d| | 24 |
| Wheel alignment incorrect which adversely affects the steering |2.5.1| | 24 |
| Headlamp not working on dipped beam |4.1.1 |a| |ii|| | 23 |
| Front shock absorber seal failed and leaking oil |2.3.3| | 23 |
| Headlamp aim not tested |1.6| | 23 |
| Locking device|s| not correctly fitted which may make the motor bicycle dangerous to ride |6.2.1h| | 22 |
| Rear Roller brake test indicates a sticking brake |3.3.A1a| | 21 |
| Stop lamp remains on when the brake is released |1.3.1e| | 20 |
| Rear wheel bearings have excessive free play |2.4.A.2c| | 19 |
| Nearside Front Front shock absorber seal failed and leaking oil |2.3.3| | 19 |
| Roller brake test The less effective brake control does not achieve an efficiency of 25%. |3.3.A2b| | 19 |
| Rear Stop lamp remains on when the brake is released |1.3.1e| | 19 |
| Front Brake excessively binding (1.2.1 (f)) | 19 |
| Rear Drive chain excessively loose |6.2.1d| | 18 |
| Rear Brake locking device missing |3.2.A1e| | 18 |
| Offside Front Front shock absorber seal failed and leaking oil |2.3.3| | 18 |
| Exhaust excessively deteriorated |7.1.1a| | 16 |
| Nearside Front Shock absorber has a serious fluid leak (5.3.2 (b)) | 16 |
| Headlamp aim not tested (4.1.2 (b)) | 15 |
| Offside Front Shock absorber has a serious fluid leak (5.3.2 (b)) | 15 |
| Nearside Handlebar handgrip not secure to handlebars. |2.1.1c| | 14 |
| Front Drive chain sprocket worn to excess |6.2.1e| | 14 |
| Rear Brake pedal has inadequate reserve travel |3.1.3b| | 14 |
| Front Floor brake test indicates a binding brake |3.3.C2c| | 14 |
| Front Front position lamp does not illuminate immediately when switched on |1.1.3a| | 13 |
| Rear Rear position lamp does not illuminate immediately when it is switched on |1.1.3a| | 13 |
| Steering headbearing excessively stiff or notchy (2.2.2 (f) (i)) | 13 |
| Rear Drive chain worn to excess |6.2.1e| | 12 |
| Headlamp not working on main beam (4.1.1 (a) (ii)) | 12 |
| Horn not working (7.7 (a)) | 12 |
| Headlamp not working on main beam |4.1.1 |a| |ii|| | 11 |
| Rear Brake reaction bracket insecure |3.2.A1j| | 11 |
| Rear Wheel alignment incorrect which adversely affects the handling |2.5.1| | 11 |
| Rear reflector on motorcycle obscured |1.4.1| | 11 |
| Rear reflector missing (4.8.2 (a) (ii)) | 11 |
| Horn not working (7.7 (a) (ii)) | 11 |
| Drive chain horseshoe locking device incorrectly fitted (6.1.7 (j) (i)) | 11 |
| Drive chain worn to excess (6.1.7 (c) (i)) | 11 |
| Front Brake excessively binding |1.2.1 |f|| | 10 |
| Throttle has a significant change in engine speed whilst moving the steering from lock to lock |2.1.4| | 10 |
| Front Brake lever has inadequate reserve travel |3.1.3b| | 10 |
| Front Brake fluid reservoir fluid level dangerously low |3.2.B1d| | 10 |
| Rear Roller brake test indicates excessive fluctuation of brake effort |3.3.A1d| | 9 |
| Locking devices not correctly fitted which may make the motor bicycle dangerous to ride |6.2.1h| | 9 |
| Drive chain sprocket carrier worn to excess |6.2.1e| | 9 |
| Rear suspension bush has excessive free play |2.4.A2a|i|| | 9 |
| Rear Wheel bearing has excessive play (5.1.3 (a) (i)) | 9 |
| Wheel alignment incorrect which adversely affects the handling (2.4 (a)) | 9 |
| Nearside Front Shock absorber has a serious fluid leak |5.3.2 |b|| | 8 |
| Front Front shock absorber seal failed and leaking oil |2.3.3| | 8 |
| Rear Locking device|s| not correctly fitted which may make the motor bicycle dangerous to ride |6.2.1h| | 8 |
| Exhaust mounting does not fully support the exhaust system |7.1.1.c| | 8 |
| Headlamp dipped beam affected by the operation of another lamp |1.2.2c| | 8 |
| Front Roller brake test indicates excessive fluctuation of brake effort |3.3.A1d| | 8 |
| Rear Brake reaction bracket securing bolt|s| loose |3.2.A1j| | 8 |
| Steering headbearing has excessive wear or free play (2.2.2 (f) (i)) | 8 |
| Roller brake test The less effective brake control does not achieve an efficiency of 25% (1.2.2 (a) (i)) | 8 |
| Brake pedal has inadequate reserve travel |3.1.3b| | 7 |
| Front Brake disc|s| friction surface contaminated by oil or grease |3.2.A1k| | 7 |
| Rear Brake lining|s| less than 1.5 mm thick |3.2.A1f|i|| | 7 |
| Front Steering headbearing has excessive free play |2.2.2| | 7 |
| Rear Brake pedal cannot be released smoothly |3.1.3d| | 7 |
| Front Floor brake test indicates a sticking brake |3.3.C2c| | 7 |
| Rear reflector on motorcycle obscured |1.4.2b| | 7 |
| Rear Floor brake test indicates a sticking brake |3.3.C2c| | 7 |
| Offside Front Shock absorber has a serious fluid leak |5.3.2 |b|| | 7 |
| Offside Handlebar handgrip not secure to handlebars. |2.1.1c| | 7 |
| Front suspension assembly component excessively corroded. |2.3.1| | 7 |
| Rear Rear wheel bearings have excessive free play |2.4.A.2c| | 7 |
| Drive chain so worn it is likely to fail (6.1.7 (c) (ii)) | 7 |
| Rear Brake excessively binding (1.2.1 (f)) | 7 |
| Rear Valve stem seriously damaged (5.2.3 (j)) | 7 |