Triumph T120 vs Yamaha FZS600

The Triumph T120 passes its MOT first time more often than the Yamaha FZS600: 91.1% vs 82.6%, a 8.5-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025

Metric	Triumph T120	Yamaha FZS600
First-time pass rate	91.1%	82.6%
Outright fail rate	3.3%	10.6%
Vs comparable bikes (age & mileage adjusted)	+4.9 pts	-0.8 pts
Engine size	650cc	599cc
Rank among all models	#659 of 5428	#3052 of 5428
Median miles at test	8,155	21,612
MOT tests analysed	5,037	136,558
Most common failure	steering and suspension	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 T120	Yamaha FZS600
Brakes	0.6%	4.5%
Lights & signalling	1.3%	3.4%
Steering & suspension	1.6%	2.7%
Tyres & wheels	0.5%	2.9%
Fuel & exhaust	0.4%	1.1%
Structure & body	0.2%	1.1%
Drive system	0.2%	0.9%

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 T120	Yamaha FZS600
2012	89.1%	80.2%
2013	90.9%	81.3%
2014	89.8%	81.2%
2015	92.6%	81.1%
2016	93.6%	82.2%
2017	91.9%	82.0%
2018	93.3%	81.3%
2019	94.4%	83.0%

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 T120	Yamaha FZS600
0k-10k miles	91.1%	89.6%
10k-20k miles	91.8%	85.5%
20k-30k miles	90.3%	81.4%
30k-40k miles	91.2%	78.7%
40k-50k miles	92.5%	76.8%
50k-60k miles	93.7%	74.7%

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

Triumph T120 vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Triumph T120 or the Yamaha FZS600?

The Triumph T120 passes its MOT first time more often than the Yamaha FZS600: 91.1% vs 82.6%, a 8.5-point lead. Adjusted for age, mileage and test class, the Triumph T120 still comes out ahead: +4.9 points vs comparable bikes for the Triumph T120, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Triumph T120 fail its MOT on most?

Steering & suspension: 1.6% of Triumph T120 MOT tests failed on it, then lights & signalling (1.3%).

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 T120 or the Yamaha FZS600?

At 50k-60k miles the Triumph T120 passes first time more often: 93.7% for the Triumph T120 vs 74.7% for the Yamaha FZS600.

TRIUMPH T120 91.1% pass · 5,037 tests YAMAHA FZS600 82.6% pass · 137k tests

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