Velocette Viper vs Suzuki DR-Z400S

The Velocette Viper 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	Velocette Viper	Suzuki DR-Z400S
First-time pass rate	93.8%	80.4%
Outright fail rate	1.7%	11.1%
Engine size	350cc	398cc
Rank among all models	#198 of 5428	#3493 of 5428
Median miles at test	15,114	6,940
MOT tests analysed	1,970	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.

What fails, side by side

share of each bike's MOT tests that failed on the component · lower is better

Component	Velocette Viper	Suzuki DR-Z400S
Lights & signalling	0.8%	6.1%
Brakes	0.4%	3.5%
Steering & suspension	0.2%	3.2%
Tyres & wheels	0.3%	2.6%
Drive system	0.1%	0.8%
Structure & body	0.1%	0.7%
Fuel & exhaust	0%	0.6%

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	Velocette Viper	Suzuki DR-Z400S
2011	92.7%	78.3%
2012	92.3%	79.8%
2013	93.6%	77.6%
2014	95.3%	78.5%
2015	94.8%	79.9%
2016	96.7%	78.4%
2017	95.3%	80.9%
2018	100.0%	79.5%

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	Velocette Viper	Suzuki DR-Z400S
0k-10k miles	93.4%	81.7%
10k-20k miles	92.6%	78.4%
20k-30k miles	92.9%	79.2%
30k-40k miles	97.0%	76.4%
40k-50k miles	92.5%	75.2%
50k-60k miles	94.5%	82.9%

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

Velocette Viper vs Suzuki DR-Z400S FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Velocette Viper or the Suzuki DR-Z400S?

The Velocette Viper passes its MOT first time more often than the Suzuki DR-Z400S: 93.8% vs 80.4%, a 13.4-point lead. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Velocette Viper fail its MOT on most?

Lights & signalling: 0.8% of Velocette Viper MOT tests failed on it, then brakes (0.4%).

What does the Suzuki DR-Z400S fail its MOT on most?

Lights & signalling: 6.1% of Suzuki DR-Z400S MOT tests failed on it, then brakes (3.5%).

Which holds up better at high mileage, the Velocette Viper or the Suzuki DR-Z400S?

At 50k-60k miles the Velocette Viper passes first time more often: 94.5% for the Velocette Viper vs 82.9% for the Suzuki DR-Z400S.

VELOCETTE VIPER 93.8% pass · 1,970 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.