Harley-Davidson FLH vs Triumph Bonneville

The Harley-Davidson FLH passes its MOT first time more often than the Triumph Bonneville: 89.5% vs 89.0%, a 0.5-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025

Metric	Harley-Davidson FLH	Triumph Bonneville
First-time pass rate	89.5%	89.0%
Outright fail rate	4.5%	5.0%
Median miles at test	17,014	7,619
MOT tests analysed	1,942	195,256
Most common failure	lighting and signalling	brakes

First-time outcomes on normal tests, 2005–2025. "Most common failure" is the component group with the most recorded defects on failed tests. Read pass rates against test counts: a smaller sample is noisier. Source: DVSA anonymised MOT results.

HARLEY-DAVIDSON FLH 89.5% pass · 1,942 tests TRIUMPH BONNEVILLE 89.0% pass · 195k tests

See each bike's full report (trend, mileage curve, failure breakdown and rivals) on its own page.