Triumph Rocket 111 Roadster vs Harley-Davidson Fxsb

The Triumph Rocket 111 Roadster passes its MOT first time more often than the Harley-Davidson Fxsb: 90.7% vs 89.3%, a 1.4-point lead.

MOT reliability, side by side

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

Metric	Triumph Rocket 111 Roadster	Harley-Davidson Fxsb
First-time pass rate	90.7%	89.3%
Outright fail rate	4.8%	4.4%
Vs comparable bikes (age & mileage adjusted)	+4.6 pts	+1.4 pts
Engine size	2,294cc	1,690cc
Rank among all models	#748 of 5428	#1180 of 5428
Median miles at test	12,447	6,609
MOT tests analysed	2,642	6,915
Most common failure	brakes	lamps and reflectors

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.

"Vs comparable bikes" is the first-time pass rate minus the rate expected for each bike's own mix of age, mileage and test class, in percentage points: positive means better than comparable bikes. How this works.

What fails, side by side

share of each bike's MOT tests that failed on the component · lower is better

Component	Triumph Rocket 111 Roadster	Harley-Davidson Fxsb
Lights & signalling	1.6%	2.8%
Tyres & wheels	1.7%	0.8%
Brakes	1.7%	0.5%
Structure & body	0.3%	0.4%
Steering & suspension	0.2%	0.4%
Fuel & exhaust	0.2%	0.0%

A test that fails on two components counts once in each. Component links go to the bikes most likely to fail on it.

Pass rate by test year

first-time MOT pass rate in each calendar year both bikes were tested

Test year	Triumph Rocket 111 Roadster	Harley-Davidson Fxsb
2018	89.8%	85.3%
2019	90.4%	88.9%
2020	90.5%	90.6%
2021	93.3%	91.1%
2022	90.0%	90.4%
2023	91.5%	90.8%
2024	89.3%	90.1%
2025	92.3%	88.7%

Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.

Pass rate by mileage

first-time MOT pass rate by miles on the clock at test

Mileage	Triumph Rocket 111 Roadster	Harley-Davidson Fxsb
0k-10k miles	92.5%	89.7%
10k-20k miles	89.9%	88.7%
20k-30k miles	89.4%	88.6%
30k-40k miles	88.6%	84.8%

Bands with fewer than 30 tests for either bike are left out.

Triumph Rocket 111 Roadster vs Harley-Davidson Fxsb FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Triumph Rocket 111 Roadster or the Harley-Davidson Fxsb?

The Triumph Rocket 111 Roadster passes its MOT first time more often than the Harley-Davidson Fxsb: 90.7% vs 89.3%, a 1.4-point lead. Adjusted for age, mileage and test class, the Triumph Rocket 111 Roadster still comes out ahead: +4.6 points vs comparable bikes for the Triumph Rocket 111 Roadster, +1.4 for the Harley-Davidson Fxsb. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Triumph Rocket 111 Roadster fail its MOT on most?

Tyres & wheels: 1.7% of Triumph Rocket 111 Roadster MOT tests failed on it, then brakes (1.7%).

What does the Harley-Davidson Fxsb fail its MOT on most?

Lights & signalling: 2.8% of Harley-Davidson Fxsb MOT tests failed on it, then tyres & wheels (0.8%).

Which holds up better at high mileage, the Triumph Rocket 111 Roadster or the Harley-Davidson Fxsb?

At 30k-40k miles the Triumph Rocket 111 Roadster passes first time more often: 88.6% for the Triumph Rocket 111 Roadster vs 84.8% for the Harley-Davidson Fxsb.

TRIUMPH ROCKET 111 ROADSTER 90.7% pass · 2,642 tests HARLEY-DAVIDSON FXSB 89.3% pass · 6,915 tests

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