BIKERELIABILITY Reg check
League table/ Ducati Diavel Carbon/vs Triumph Bonneville
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Ducati Diavel Carbon vs Triumph Bonneville

The Triumph Bonneville passes its MOT first time more often than the Ducati Diavel Carbon: 89.0% vs 88.7%, a 0.3-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Ducati Diavel Carbon Triumph Bonneville
First-time pass rate 88.7% 89.0%
Outright fail rate 6.0% 5.0%
Vs comparable bikes (age & mileage adjusted) +1.2 pts +1.6 pts
Engine size 1,198cc 865cc
Rank among all models #1370 of 5428 #1269 of 5428
Median miles at test 8,289 7,619
MOT tests analysed 2,884 195,256
Most common failure brakes 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 Ducati Diavel Carbon Triumph Bonneville
Lights & signalling 2.0% 1.9%
Brakes 1.4% 1.9%
Tyres & wheels 1.5% 1.1%
Steering & suspension 1.5% 0.7%
Structure & body 0.4% 0.5%
Fuel & exhaust 0.2% 0.3%
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 Diavel Carbon Triumph Bonneville
2018 85.1% 88.7%
2019 88.8% 88.9%
2020 90.1% 91.1%
2021 89.2% 89.6%
2022 85.7% 89.4%
2023 91.2% 90.1%
2024 92.9% 90.6%
2025 89.0% 91.0%

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 Diavel Carbon Triumph Bonneville
0k-10k miles 89.9% 90.6%
10k-20k miles 87.0% 86.8%
20k-30k miles 84.7% 85.1%
30k-40k miles 91.8% 85.8%

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

Ducati Diavel Carbon vs Triumph Bonneville FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Ducati Diavel Carbon or the Triumph Bonneville?

The Triumph Bonneville passes its MOT first time more often than the Ducati Diavel Carbon: 89.0% vs 88.7%, a 0.3-point lead. Adjusted for age, mileage and test class the two are level (+1.2 vs +1.6 points against comparable bikes), so the raw gap is mostly down to how old and how used each fleet is. An MOT checks roadworthiness items, not engine or gearbox internals.

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

Lights & signalling: 2.0% of Ducati Diavel Carbon MOT tests failed on it, then tyres & wheels (1.5%).

What does the Triumph Bonneville fail its MOT on most?

Lights & signalling: 1.9% of Triumph Bonneville MOT tests failed on it, then brakes (1.9%).

Which holds up better at high mileage, the Ducati Diavel Carbon or the Triumph Bonneville?

At 30k-40k miles the Ducati Diavel Carbon passes first time more often: 91.8% for the Ducati Diavel Carbon vs 85.8% for the Triumph Bonneville.

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