BIKERELIABILITY Reg check
League table/ Ducati Monster S2R/vs Triumph Street Triple
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Ducati Monster S2R vs Triumph Street Triple

The Triumph Street Triple passes its MOT first time more often than the Ducati Monster S2R: 87.7% vs 85.4%, a 2.3-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Ducati Monster S2R Triumph Street Triple
First-time pass rate 85.4% 87.7%
Outright fail rate 7.3% 5.9%
Vs comparable bikes (age & mileage adjusted) -1.3 pts +1.3 pts
Engine size 803cc 675cc
Rank among all models #2385 of 5428 #1695 of 5428
Median miles at test 9,604 11,189
MOT tests analysed 1,974 37,699
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 Monster S2R Triumph Street Triple
Lights & signalling 3.9% 2.6%
Brakes 2.5% 1.6%
Steering & suspension 1.6% 1.2%
Tyres & wheels 1.5% 1.2%
Structure & body 0.6% 0.7%
Drive system 0.7% 0.2%
Fuel & exhaust 0.2% 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 Monster S2R Triumph Street Triple
2018 80.5% 87.8%
2019 73.3% 87.9%
2020 85.3% 89.6%
2021 84.1% 87.2%
2022 85.7% 87.3%
2023 89.2% 87.5%
2024 85.1% 88.0%
2025 85.9% 86.4%

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 Monster S2R Triumph Street Triple
0k-10k miles 88.7% 91.3%
10k-20k miles 82.8% 86.7%
20k-30k miles 79.0% 82.7%
30k-40k miles 85.5% 79.9%

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

Ducati Monster S2R vs Triumph Street Triple FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Ducati Monster S2R or the Triumph Street Triple?

The Triumph Street Triple passes its MOT first time more often than the Ducati Monster S2R: 87.7% vs 85.4%, a 2.3-point lead. Adjusted for age, mileage and test class, the Triumph Street Triple still comes out ahead: -1.3 points vs comparable bikes for the Ducati Monster S2R, +1.3 for the Triumph Street Triple. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Ducati Monster S2R fail its MOT on most?

Lights & signalling: 3.9% of Ducati Monster S2R MOT tests failed on it, then brakes (2.5%).

What does the Triumph Street Triple fail its MOT on most?

Lights & signalling: 2.6% of Triumph Street Triple MOT tests failed on it, then brakes (1.6%).

Which holds up better at high mileage, the Ducati Monster S2R or the Triumph Street Triple?

At 30k-40k miles the Ducati Monster S2R passes first time more often: 85.5% for the Ducati Monster S2R vs 79.9% for the Triumph Street Triple.

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