Know Your MOT

Triumph Bonneville vs Triumph Stag: MOT reliability compared

Updated 05 September 2026.

9.8%
Triumph Bonneville MOT failure rate, 12.8 pts lower than Triumph Stag

Triumph Bonneville is the more reliable MOT performer: 9.8% of Triumph Bonneville MOTs fail versus 22.6% for Triumph Stag, a 12.8 point gap.

MetricTriumph BonnevilleTriumph Stag
MOT failure rate9.8%22.6%
Tests analysed305,24887,808
Most common failureBrakes (19.7%)Lamps & electrical (40.6%)

Questions and answers

Which is more reliable, Triumph Bonneville or Triumph Stag?

Triumph Bonneville is the more reliable MOT performer: 9.8% of Triumph Bonneville MOTs fail versus 22.6% for Triumph Stag, a 12.8 point gap.

What is the MOT failure rate of the Triumph Bonneville?

9.8% of Triumph Bonneville MOT tests result in a failure, from 305,248 tests.

What is the MOT failure rate of the Triumph Stag?

22.6% of Triumph Stag MOT tests result in a failure, from 87,808 tests.

Compared here

Triumph Bonneville common MOT failures and failure rateTriumph Stag common MOT failures and failure rate