Ariel NH vs Yamaha RD350

The Ariel NH passes its MOT first time more often than the Yamaha RD350: 92.4% vs 86.3%, a 6.1-point lead.

MOT reliability, side by side

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

Metric	Ariel NH	Yamaha RD350
First-time pass rate	92.4%	86.3%
Outright fail rate	1.8%	6.6%
Engine size	350cc	347cc
Rank among all models	#405 of 5428	#2120 of 5428
Median miles at test	12,122	23,256
MOT tests analysed	342	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.

Pass rate by test year

first-time MOT pass rate in each calendar year both bikes were tested

Test year	Ariel NH	Yamaha RD350
2006	94.2%	79.9%
2007	97.9%	81.2%
2008	87.5%	79.7%
2009	93.3%	80.6%
2010	93.6%	81.9%
2011	91.5%	82.2%
2012	87.8%	84.7%

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	Ariel NH	Yamaha RD350
0k-10k miles	91.7%	88.9%
10k-20k miles	95.7%	87.5%
20k-30k miles	87.8%	85.5%

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

ARIEL NH 92.4% pass · 342 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.