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

Data as of: DVSA MOT results to 2025

Ducati Diavel vs Triumph Bonneville

The Ducati Diavel passes its MOT first time more often than the Triumph Bonneville: 90.3% vs 89.0%, a 1.3-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Ducati Diavel Triumph Bonneville
First-time pass rate 90.3% 89.0%
Outright fail rate 5.4% 5.0%
Vs comparable bikes (age & mileage adjusted) +2.8 pts +1.6 pts
Engine size 1,198cc 865cc
Rank among all models #854 of 5428 #1269 of 5428
Median miles at test 8,340 7,619
MOT tests analysed 8,740 195,256
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 Ducati Diavel Triumph Bonneville
Lights & signalling 1.8% 1.9%
Brakes 1.4% 1.9%
Steering & suspension 1.4% 0.7%
Tyres & wheels 1.0% 1.1%
Structure & body 0.4% 0.5%
Fuel & exhaust 0.1% 0.3%
Drive system 0.0% 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 Triumph Bonneville
2018 89.7% 88.7%
2019 89.3% 88.9%
2020 92.0% 91.1%
2021 91.8% 89.6%
2022 91.7% 89.4%
2023 90.2% 90.1%
2024 90.7% 90.6%
2025 92.6% 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 Triumph Bonneville
0k-10k miles 91.7% 90.6%
10k-20k miles 88.8% 86.8%
20k-30k miles 85.9% 85.1%
30k-40k miles 87.8% 85.8%

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

Ducati Diavel vs Triumph Bonneville FAQ

answers computed from the data above · terms in the glossary

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

The Ducati Diavel passes its MOT first time more often than the Triumph Bonneville: 90.3% vs 89.0%, a 1.3-point lead. Adjusted for age, mileage and test class, the Ducati Diavel still comes out ahead: +2.8 points vs comparable bikes for the Ducati Diavel, +1.6 for the Triumph Bonneville. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Ducati Diavel fail its MOT on most?

Lights & signalling: 1.8% of Ducati Diavel MOT tests failed on it, then brakes (1.4%).

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 or the Triumph Bonneville?

At 30k-40k miles the Ducati Diavel passes first time more often: 87.8% for the Ducati Diavel vs 85.8% for the Triumph Bonneville.

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