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Triumph Bonneville t vs Triumph Unknown: reliability comparison

MOT pass rates, common faults and mileage compared from real UK MOT data.

Triumph Bonneville t
90%
MOT pass rate · 2 vehicles
Triumph Unknown
89%
MOT pass rate · 65,927 vehicles
Verdict: On MOT pass rate the Triumph Bonneville t (90%) and Triumph Unknown (89%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Head to head

Measure Triumph Bonneville t Triumph Unknown
MOT pass rate 90% ✓ 89%
MOT failure rate 10% ✓ 11%
Faults & advisories per test 0.5 ✓ 0.6
Dangerous-fault share 0% ✓ 2%
Average mileage 10,081 mi 16,601 mi
Sample size (vehicles) 2 65,927

Most common faults

Triumph Bonneville t

  1. Drive chain excessively loose (6.2.1d)
  2. Front Brake disc(s) slightly scored (3.2.A1l)
  3. Drive chain slightly loose (6.1.7 (c) (i))
  4. Front Brake pad(s) close to minimum limit (1.1.13 (a))
  5. Rear Brake disc(s) slightly worn (3.2.A1l)
  6. Rear Brake pad(s) less than 1.5 mm thick (3.2.A1f(i))

Triumph Unknown

  1. Exhaust noisy (8.1.1 (a))
  2. Exhaust noisy (7.1.2)
  3. Front Roller brake test indicates slight fluctuation of brake effort (3.3.A1d)
  4. COVID-19 6 MONTH EXTENSION
  5. Rear Tyre worn close to the legal limit (5.2.3 (e))
  6. Steering headbearing has slight free play (2.2.2)

Reliability FAQ

On MOT pass rate the Triumph Bonneville t (90%) and Triumph Unknown (89%) are very close — weigh the individual measures below, and remember condition depends on age, mileage and upkeep.

Full Triumph Bonneville t report Full Triumph Unknown report Most reliable cars

Pass rates are computed over completed (pass/fail) MOT tests. Reliability also depends on age, mileage and upkeep — see each model's page for the full picture.