BIKERELIABILITY Reg check
League table/ Ducati X Diavel/vs Harley-Davidson Flstc
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Ducati X Diavel vs Harley-Davidson Flstc

The Ducati X Diavel and Harley-Davidson Flstc have an identical 89.4% first-time MOT pass rate.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Ducati X Diavel Harley-Davidson Flstc
First-time pass rate 89.4% 89.4%
Outright fail rate 7.7% 4.9%
Vs comparable bikes (age & mileage adjusted) +0.6 pts +5.1 pts
Engine size 1,262cc 1,450cc
Rank among all models #1147 of 5428 #1147 of 5428
Median miles at test 5,832 16,884
MOT tests analysed 3,445 23,752
Most common failure brakes lighting and signalling

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 Ducati X Diavel Harley-Davidson Flstc
Brakes 5.0% 1.4%
Lights & signalling 1.5% 2.0%
Tyres & wheels 1.0% 1.1%
Steering & suspension 0.8% 0.5%
Structure & body 0.5% 0.2%
Fuel & exhaust 0% 0.5%
Drive system 0% 0.1%

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 Ducati X Diavel Harley-Davidson Flstc
2019 90.4% 89.0%
2020 90.2% 91.4%
2021 87.9% 90.7%
2022 88.5% 92.3%
2023 89.2% 90.7%
2024 90.2% 90.4%
2025 90.4% 91.4%

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 Ducati X Diavel Harley-Davidson Flstc
0k-10k miles 89.3% 90.8%
10k-20k miles 89.6% 89.6%
20k-30k miles 85.1% 88.4%

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

Ducati X Diavel vs Harley-Davidson Flstc FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Ducati X Diavel or the Harley-Davidson Flstc?

The Ducati X Diavel and Harley-Davidson Flstc have an identical 89.4% first-time MOT pass rate. Adjusted for age, mileage and test class, the Harley-Davidson Flstc still comes out ahead: +0.6 points vs comparable bikes for the Ducati X Diavel, +5.1 for the Harley-Davidson Flstc. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Ducati X Diavel fail its MOT on most?

Brakes: 5.0% of Ducati X Diavel MOT tests failed on it, then lights & signalling (1.5%).

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

Lights & signalling: 2.0% of Harley-Davidson Flstc MOT tests failed on it, then brakes (1.4%).

Which holds up better at high mileage, the Ducati X Diavel or the Harley-Davidson Flstc?

At 20k-30k miles the Harley-Davidson Flstc passes first time more often: 85.1% for the Ducati X Diavel vs 88.4% for the Harley-Davidson Flstc.

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