Harley-Davidson Flhxs Street Glide SP 1868 19 vs Triumph Rocket Iii

The Harley-Davidson Flhxs Street Glide SP 1868 19 passes its MOT first time more often than the Triumph Rocket Iii: 94.9% vs 88.3%, a 6.6-point lead.

MOT reliability, side by side

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

Metric	Harley-Davidson Flhxs Street Glide SP 1868 19	Triumph Rocket Iii
First-time pass rate	94.9%	88.3%
Outright fail rate	2.3%	6.1%
Vs comparable bikes (age & mileage adjusted)	+7.6 pts	+2.7 pts
Engine size	1,868cc	2,294cc
Rank among all models	#82 of 5428	#1505 of 5428
Median miles at test	10,319	13,110
MOT tests analysed	513	15,488
Most common failure	lamps and reflectors	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.

"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	Harley-Davidson Flhxs Street Glide SP 1868 19	Triumph Rocket Iii
Lights & signalling	1.2%	2.3%
Tyres & wheels	0.8%	2.0%
Brakes	0.6%	1.8%
Steering & suspension	0.6%	0.7%
Fuel & exhaust	0%	0.6%
Structure & body	0%	0.2%

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	Harley-Davidson Flhxs Street Glide SP 1868 19	Triumph Rocket Iii
2022	93.1%	88.7%
2023	94.2%	89.3%
2024	94.9%	90.7%
2025	98.2%	88.3%

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	Harley-Davidson Flhxs Street Glide SP 1868 19	Triumph Rocket Iii
0k-10k miles	96.2%	89.2%
10k-20k miles	94.4%	88.6%
20k-30k miles	90.4%	87.7%

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

Harley-Davidson Flhxs Street Glide SP 1868 19 vs Triumph Rocket Iii FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Harley-Davidson Flhxs Street Glide SP 1868 19 or the Triumph Rocket Iii?

The Harley-Davidson Flhxs Street Glide SP 1868 19 passes its MOT first time more often than the Triumph Rocket Iii: 94.9% vs 88.3%, a 6.6-point lead. Adjusted for age, mileage and test class, the Harley-Davidson Flhxs Street Glide SP 1868 19 still comes out ahead: +7.6 points vs comparable bikes for the Harley-Davidson Flhxs Street Glide SP 1868 19, +2.7 for the Triumph Rocket Iii. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Harley-Davidson Flhxs Street Glide SP 1868 19 fail its MOT on most?

Lights & signalling: 1.2% of Harley-Davidson Flhxs Street Glide SP 1868 19 MOT tests failed on it, then tyres & wheels (0.8%).

What does the Triumph Rocket Iii fail its MOT on most?

Lights & signalling: 2.3% of Triumph Rocket Iii MOT tests failed on it, then tyres & wheels (2.0%).

Which holds up better at high mileage, the Harley-Davidson Flhxs Street Glide SP 1868 19 or the Triumph Rocket Iii?

At 20k-30k miles the Harley-Davidson Flhxs Street Glide SP 1868 19 passes first time more often: 90.4% for the Harley-Davidson Flhxs Street Glide SP 1868 19 vs 87.7% for the Triumph Rocket Iii.

HARLEY-DAVIDSON FLHXS STREET GLIDE SP 1868 19 94.9% pass · 513 tests TRIUMPH ROCKET III 88.3% pass · 15.5k tests

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