Harley-Davidson Flhxse Cvo Sglide 1923 18 vs Triumph Rocket Iii

The Harley-Davidson Flhxse Cvo Sglide 1923 18 passes its MOT first time more often than the Triumph Rocket Iii: 97.5% vs 88.3%, a 9.2-point lead.

MOT reliability, side by side

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

Metric	Harley-Davidson Flhxse Cvo Sglide 1923 18	Triumph Rocket Iii
First-time pass rate	97.5%	88.3%
Outright fail rate	0.5%	6.1%
Vs comparable bikes (age & mileage adjusted)	+10.2 pts	+2.7 pts
Engine size	1,923cc	2,294cc
Median miles at test	10,868	13,110
MOT tests analysed	197	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.

Pass rate by test year

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

Test year	Harley-Davidson Flhxse Cvo Sglide 1923 18	Triumph Rocket Iii
2021	97.6%	88.5%
2022	95.7%	88.7%
2023	97.5%	89.3%
2024	100.0%	90.7%
2025	97.1%	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 Flhxse Cvo Sglide 1923 18	Triumph Rocket Iii
0k-10k miles	98.9%	89.2%
10k-20k miles	98.7%	88.6%

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

HARLEY-DAVIDSON FLHXSE CVO SGLIDE 1923 18 97.5% pass · 197 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.