2009 Triumph Bonneville 0.9L Petrol · AV09 SZZ

The 2018 failure represents the singular significant event in a otherwise pristine MOT history spanning 2018 to 2025, where every subsequent test since then has been a clean pass with no recorded defects. This pattern of consistent roadworthiness suggests the engine, transmission and core drivetrain have remained intact, while the 2018 failure likely stemmed from specific load conditions rather than general degradation. The most recent test on 2025-08-16 confirmed the vehicle remains within legal limits, though the earlier 2018 incident warrants attention given its proximity to the current age of the car. With approximately 12,565 miles recorded on a model that is now seventeen years old, the annual mileage accumulation works out to roughly 739 miles per year, a figure considerably lower than typical usage patterns for vehicles of this make and model. While the testing interval between the 2022 and 2023 MOTs compressed to just four months, the steady progression of passes indicates routine servicing has been maintained. However, the absence of any new failures following the 2018 incident suggests either reduced driving demand or extended periods of non-use, both of which would limit the expected rate of wear on suspension bushings, brake pads and rubber components compared to a continuously driven counterpart. The 2018 failure specifically highlighted an excessively tight drive chain (adverse condition 6.1.7 (k) (i)), which could manifest during a test drive as a distinct metallic clatter or increased vibration when traversing uneven surfaces, particularly around corners or when accelerating under load. Additionally, the same period saw two minor adjunct failures—a non-functional front position lamp and misalignment of the headlamp aiming beam—which are not safety-critical but should still be verified for proper operation. Given the chain tension issue, a thorough inspection of the chain routing, sprocket alignment and bearing condition is essential before committing to purchase. On a test drive, pay close attention to the rear axle for any play or grinding sounds that might indicate worn bushings or deteriorating leaf spring attachments, and monitor the braking system for any change in pedal feel or pad wear consistency across the front and rear discs. The drive chain itself should be inspected visually for excessive slack, corrosion or missing links, and its tension should be checked against manufacturer specifications—any audible rattling or skipping over bumps would confirm the 2018 finding. Finally, verify that all electrical indicators function correctly, especially the front position lamp and headlamp aim, to ensure the full range of lighting systems operate as intended.