Ariel NH350 vs Yamaha RD350

The Ariel NH350 passes its MOT first time more often than the Yamaha RD350: 93.6% vs 86.3%, a 7.3-point lead.

MOT reliability, side by side

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

Metric	Ariel NH350	Yamaha RD350
First-time pass rate	93.6%	86.3%
Outright fail rate	3.5%	6.6%
Engine size	350cc	347cc
Rank among all models	#224 of 5428	#2120 of 5428
Median miles at test	26,315	23,256
MOT tests analysed	282	19,574
Most common failure	brakes	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 NH350	Yamaha RD350
2006	97.7%	79.9%
2007	100.0%	81.2%
2008	87.9%	79.7%
2009	91.9%	80.6%
2011	94.9%	82.2%

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 NH350	Yamaha RD350
0k-10k miles	93.5%	88.9%
20k-30k miles	92.9%	85.5%
30k-40k miles	92.5%	85.3%
40k-50k miles	90.6%	83.7%

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

ARIEL NH350 93.6% pass · 282 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.