BIKERELIABILITY Reg check
League table/ Triumph TT600/vs Yamaha FZS600
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Triumph TT600 vs Yamaha FZS600

The Yamaha FZS600 passes its MOT first time more often than the Triumph TT600: 82.6% vs 79.9%, a 2.7-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Triumph TT600 Yamaha FZS600
First-time pass rate 79.9% 82.6%
Outright fail rate 12.5% 10.6%
Vs comparable bikes (age & mileage adjusted) -5.0 pts -0.8 pts
Engine size 599cc 599cc
Rank among all models #3603 of 5428 #3052 of 5428
Median miles at test 15,568 21,612
MOT tests analysed 15,432 136,558
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 Triumph TT600 Yamaha FZS600
Brakes 4.3% 4.5%
Lights & signalling 5.3% 3.4%
Steering & suspension 4.7% 2.7%
Tyres & wheels 2.5% 2.9%
Structure & body 1.3% 1.1%
Drive system 1.0% 0.9%
Fuel & exhaust 0.4% 1.1%

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 Triumph TT600 Yamaha FZS600
2018 81.5% 81.3%
2019 80.6% 83.0%
2020 80.3% 83.6%
2021 80.3% 82.8%
2022 81.3% 83.6%
2023 80.7% 84.2%
2024 84.6% 83.3%
2025 79.1% 84.0%

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 Triumph TT600 Yamaha FZS600
0k-10k miles 86.9% 89.6%
10k-20k miles 79.5% 85.5%
20k-30k miles 75.8% 81.4%
30k-40k miles 73.1% 78.7%
40k-50k miles 74.4% 76.8%
50k-60k miles 76.9% 74.7%

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

Triumph TT600 vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Triumph TT600 or the Yamaha FZS600?

The Yamaha FZS600 passes its MOT first time more often than the Triumph TT600: 82.6% vs 79.9%, a 2.7-point lead. Adjusted for age, mileage and test class, the Yamaha FZS600 still comes out ahead: -5.0 points vs comparable bikes for the Triumph TT600, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Triumph TT600 fail its MOT on most?

Lights & signalling: 5.3% of Triumph TT600 MOT tests failed on it, then steering & suspension (4.7%).

What does the Yamaha FZS600 fail its MOT on most?

Brakes: 4.5% of Yamaha FZS600 MOT tests failed on it, then lights & signalling (3.4%).

Which holds up better at high mileage, the Triumph TT600 or the Yamaha FZS600?

At 50k-60k miles the Triumph TT600 passes first time more often: 76.9% for the Triumph TT600 vs 74.7% for the Yamaha FZS600.

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