Norton 18 vs Suzuki GSF600

The Norton 18 passes its MOT first time more often than the Suzuki GSF600: 95.1% vs 77.3%, a 17.8-point lead.

MOT reliability, side by side

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

Metric	Norton 18	Suzuki GSF600
First-time pass rate	95.1%	77.3%
Outright fail rate	1.3%	14.2%
Engine size	497cc	599cc
Rank among all models	#67 of 5428	#4013 of 5428
Median miles at test	10,096	21,080
MOT tests analysed	387	143,023
Most common failure	brakes	brakes

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	Norton 18	Suzuki GSF600
2006	95.3%	81.8%
2007	98.0%	80.0%
2008	95.6%	78.4%
2009	93.2%	75.8%
2010	96.0%	75.8%
2011	93.5%	76.1%
2012	91.2%	75.9%

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	Norton 18	Suzuki GSF600
0k-10k miles	95.4%	86.8%
10k-20k miles	97.3%	80.1%

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

NORTON 18 95.1% pass · 387 tests SUZUKI GSF600 77.3% pass · 143k tests

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