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

Data as of: DVSA MOT results to 2025

Honda Shadow vs Triumph Bonneville

The Triumph Bonneville passes its MOT first time more often than the Honda Shadow: 89.0% vs 81.0%, a 8.0-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Honda Shadow Triumph Bonneville
First-time pass rate 81.0% 89.0%
Outright fail rate 11.2% 5.0%
Vs comparable bikes (age & mileage adjusted) -1.0 pts +1.6 pts
Engine size 700cc 865cc
Rank among all models #3379 of 5428 #1269 of 5428
Median miles at test 18,246 7,619
MOT tests analysed 6,066 195,256
Most common failure lighting and signalling 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 Honda Shadow Triumph Bonneville
Lights & signalling 4.8% 1.9%
Brakes 3.7% 1.9%
Tyres & wheels 3.1% 1.1%
Steering & suspension 3.1% 0.7%
Structure & body 0.9% 0.5%
Fuel & exhaust 0.7% 0.3%
Drive system 0.5% 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 Honda Shadow Triumph Bonneville
2018 80.6% 88.7%
2019 83.6% 88.9%
2020 83.4% 91.1%
2021 78.5% 89.6%
2022 83.5% 89.4%
2023 82.2% 90.1%
2024 85.4% 90.6%
2025 78.6% 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 Honda Shadow Triumph Bonneville
0k-10k miles 87.3% 90.6%
10k-20k miles 81.5% 86.8%
20k-30k miles 77.7% 85.1%
30k-40k miles 75.9% 85.8%
40k-50k miles 78.8% 86.0%
50k-60k miles 72.8% 86.6%

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

Honda Shadow vs Triumph Bonneville FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Honda Shadow or the Triumph Bonneville?

The Triumph Bonneville passes its MOT first time more often than the Honda Shadow: 89.0% vs 81.0%, a 8.0-point lead. Adjusted for age, mileage and test class, the Triumph Bonneville still comes out ahead: -1.0 points vs comparable bikes for the Honda Shadow, +1.6 for the Triumph Bonneville. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Honda Shadow fail its MOT on most?

Lights & signalling: 4.8% of Honda Shadow MOT tests failed on it, then brakes (3.7%).

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 Honda Shadow or the Triumph Bonneville?

At 50k-60k miles the Triumph Bonneville passes first time more often: 72.8% for the Honda Shadow vs 86.6% for the Triumph Bonneville.

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