Triumph 21 vs Suzuki DR-Z400S

The Triumph 21 passes its MOT first time more often than the Suzuki DR-Z400S: 93.8% vs 80.4%, a 13.4-point lead.

MOT reliability, side by side

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

Metric	Triumph 21	Suzuki DR-Z400S
First-time pass rate	93.8%	80.4%
Outright fail rate	2.2%	11.1%
Engine size	350cc	398cc
Rank among all models	#198 of 5428	#3493 of 5428
Median miles at test	19,231	6,940
MOT tests analysed	451	26,773
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	Triumph 21	Suzuki DR-Z400S
2007	91.4%	83.1%
2008	92.9%	80.5%
2009	94.9%	78.2%
2010	97.9%	78.9%
2011	93.8%	78.3%
2012	95.6%	79.8%
2013	93.3%	77.6%
2014	83.3%	78.5%

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 21	Suzuki DR-Z400S
0k-10k miles	90.6%	81.7%
10k-20k miles	93.7%	78.4%
20k-30k miles	94.6%	79.2%
30k-40k miles	92.2%	76.4%
40k-50k miles	96.9%	75.2%
50k-60k miles	97.2%	82.9%

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

TRIUMPH 21 93.8% pass · 451 tests SUZUKI DR-Z400S 80.4% pass · 26.8k tests

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