BIKERELIABILITY Reg check
League table/ Kawasaki Z900/vs Triumph Street Triple
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Kawasaki Z900 vs Triumph Street Triple

The Triumph Street Triple passes its MOT first time more often than the Kawasaki Z900: 87.7% vs 86.9%, a 0.8-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Kawasaki Z900 Triumph Street Triple
First-time pass rate 86.9% 87.7%
Outright fail rate 5.9% 5.9%
Vs comparable bikes (age & mileage adjusted) +2.5 pts +1.3 pts
Engine size 903cc 675cc
Rank among all models #1937 of 5428 #1695 of 5428
Median miles at test 27,446 11,189
MOT tests analysed 4,100 37,699
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 Kawasaki Z900 Triumph Street Triple
Lights & signalling 3.4% 2.6%
Brakes 1.4% 1.6%
Steering & suspension 1.7% 1.2%
Tyres & wheels 1.0% 1.2%
Structure & body 0.3% 0.7%
Drive system 0.5% 0.2%
Fuel & exhaust 0.4% 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 Kawasaki Z900 Triumph Street Triple
2015 85.8% 88.5%
2016 89.4% 87.6%
2017 85.7% 88.3%
2018 92.7% 87.8%
2019 93.3% 87.9%
2020 92.7% 89.6%
2021 95.6% 87.2%
2022 90.0% 87.3%

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 Kawasaki Z900 Triumph Street Triple
0k-10k miles 86.8% 91.3%
10k-20k miles 87.7% 86.7%
20k-30k miles 87.2% 82.7%
30k-40k miles 86.3% 79.9%
40k-50k miles 88.1% 74.6%
50k-60k miles 86.1% 75.6%

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

Kawasaki Z900 vs Triumph Street Triple FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Kawasaki Z900 or the Triumph Street Triple?

The Triumph Street Triple passes its MOT first time more often than the Kawasaki Z900: 87.7% vs 86.9%, a 0.8-point lead. Adjusted for age, mileage and test class, the Kawasaki Z900 still comes out ahead: +2.5 points vs comparable bikes for the Kawasaki Z900, +1.3 for the Triumph Street Triple. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Kawasaki Z900 fail its MOT on most?

Lights & signalling: 3.4% of Kawasaki Z900 MOT tests failed on it, then steering & suspension (1.7%).

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 Kawasaki Z900 or the Triumph Street Triple?

At 50k-60k miles the Kawasaki Z900 passes first time more often: 86.1% for the Kawasaki Z900 vs 75.6% for the Triumph Street Triple.

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