Triumph 3TA vs Yamaha RD350

The Triumph 3TA passes its MOT first time more often than the Yamaha RD350: 91.3% vs 86.3%, a 5.0-point lead.

MOT reliability, side by side

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

Metric	Triumph 3TA	Yamaha RD350
First-time pass rate	91.3%	86.3%
Outright fail rate	3.5%	6.6%
Vs comparable bikes (age & mileage adjusted)	+1.6 pts	+2.4 pts
Engine size	350cc	347cc
Rank among all models	#619 of 5428	#2120 of 5428
Median miles at test	12,556	23,256
MOT tests analysed	3,243	19,574
Most common failure	lighting and signalling	lighting and signalling

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 3TA	Yamaha RD350
Lights & signalling	1.6%	3.2%
Steering & suspension	1.6%	2.5%
Brakes	0.8%	2.7%
Tyres & wheels	0.6%	0.9%
Fuel & exhaust	0.5%	0.4%
Drive system	0.1%	0.5%
Structure & body	0.2%	0.4%

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 3TA	Yamaha RD350
2011	90.9%	82.2%
2012	91.3%	84.7%
2013	91.3%	85.8%
2014	90.9%	86.6%
2015	92.0%	85.3%
2016	92.6%	88.8%
2017	92.2%	88.0%
2018	96.4%	88.8%

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 3TA	Yamaha RD350
0k-10k miles	90.4%	88.9%
10k-20k miles	90.5%	87.5%
20k-30k miles	89.8%	85.5%
30k-40k miles	94.6%	85.3%
40k-50k miles	93.9%	83.7%
50k-60k miles	92.9%	83.0%

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

Triumph 3TA vs Yamaha RD350 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Triumph 3TA or the Yamaha RD350?

The Triumph 3TA passes its MOT first time more often than the Yamaha RD350: 91.3% vs 86.3%, a 5.0-point lead. Adjusted for age, mileage and test class the two are level (+1.6 vs +2.4 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 Triumph 3TA fail its MOT on most?

Lights & signalling: 1.6% of Triumph 3TA MOT tests failed on it, then steering & suspension (1.6%).

What does the Yamaha RD350 fail its MOT on most?

Lights & signalling: 3.2% of Yamaha RD350 MOT tests failed on it, then brakes (2.7%).

Which holds up better at high mileage, the Triumph 3TA or the Yamaha RD350?

At 50k-60k miles the Triumph 3TA passes first time more often: 92.9% for the Triumph 3TA vs 83.0% for the Yamaha RD350.

TRIUMPH 3TA 91.3% pass · 3,243 tests YAMAHA RD350 86.3% pass · 19.6k tests

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