2017 Triumph Thunderbird 1.7L Petrol · TR66 STM

The vehicle is currently roadworthy but the maintenance trend shows a recent decline in the braking system integrity. While the most recent test in April 2026 at 19,890 miles passed, the tester flagged multiple advisories related to corrosion and mechanical binding. Specifically, corrosion noted on the front and rear brake hose ferrules and central rear inner and lower brake pipes, combined with a binding rear brake, indicates the beginning of age-related hydraulic degradation that requires proactive attention. The mileage pattern is exceptionally low for a nine-year-old motorcycle, averaging approximately 2,210 miles per year. There is a significant gap in usage between December 2023 at 19,815 miles and the January 2025 test at 19,886 miles, during which only 71 miles were covered over fourteen months. This suggests the bike sits stationary for long periods, which often explains the mechanical issues seen in the January 2025 failure where the throttle was found to operate incorrectly before being rectified for the subsequent re-test. A buyer must conduct a thorough physical inspection of the braking assembly to determine if the corrosion on the ferrules and pipes has compromised structural integrity. The reported rear brake binding should be checked for seized caliper pistons or perished seals, which are common symptoms of low-mileage vehicles sitting idle. One should also verify the condition of the rubber components and tyres for cracking or flat-spot, as these parts age through time rather than through mileage.