BIKERELIABILITY Reg check
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Harley-Davidson XL 883 R Sportster vs Triumph Bonneville

The Triumph Bonneville passes its MOT first time more often than the Harley-Davidson XL 883 R Sportster: 89.0% vs 88.6%, a 0.4-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Harley-Davidson XL 883 R Sportster Triumph Bonneville
First-time pass rate 88.6% 89.0%
Outright fail rate 4.7% 5.0%
Vs comparable bikes (age & mileage adjusted) +1.8 pts +1.6 pts
Engine size 883cc 865cc
Rank among all models #1402 of 5428 #1269 of 5428
Median miles at test 8,842 7,619
MOT tests analysed 4,296 195,256
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 Harley-Davidson XL 883 R Sportster Triumph Bonneville
Lights & signalling 2.3% 1.9%
Brakes 1.5% 1.9%
Tyres & wheels 0.8% 1.1%
Steering & suspension 0.7% 0.7%
Structure & body 0.3% 0.5%
Fuel & exhaust 0.4% 0.3%
Drive system 0.1% 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 Harley-Davidson XL 883 R Sportster Triumph Bonneville
2018 86.0% 88.7%
2019 88.8% 88.9%
2020 91.5% 91.1%
2021 89.1% 89.6%
2022 86.4% 89.4%
2023 86.0% 90.1%
2024 89.7% 90.6%
2025 87.9% 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 Harley-Davidson XL 883 R Sportster Triumph Bonneville
0k-10k miles 90.4% 90.6%
10k-20k miles 87.1% 86.8%
20k-30k miles 85.0% 85.1%
30k-40k miles 80.9% 85.8%
50k-60k miles 90.0% 86.6%

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

Harley-Davidson XL 883 R Sportster vs Triumph Bonneville FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Harley-Davidson XL 883 R Sportster or the Triumph Bonneville?

The Triumph Bonneville passes its MOT first time more often than the Harley-Davidson XL 883 R Sportster: 89.0% vs 88.6%, a 0.4-point lead. Adjusted for age, mileage and test class the two are level (+1.8 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 Harley-Davidson XL 883 R Sportster fail its MOT on most?

Lights & signalling: 2.3% of Harley-Davidson XL 883 R Sportster MOT tests failed on it, then brakes (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 Harley-Davidson XL 883 R Sportster or the Triumph Bonneville?

At 50k-60k miles the Harley-Davidson XL 883 R Sportster passes first time more often: 90.0% for the Harley-Davidson XL 883 R Sportster vs 86.6% for the Triumph Bonneville.

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