Vulcan Harrier vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the Vulcan Harrier: 71.0% vs 49.2%, a 21.8-point lead.

MOT reliability, side by side

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

Metric	Vulcan Harrier	Yamaha YBR 125
First-time pass rate	49.2%	71.0%
Outright fail rate	37.0%	17.1%
Vs comparable bikes (age & mileage adjusted)	-24.3 pts	-1.1 pts
Engine size	124cc	124cc
Rank among all models	#5398 of 5428	#4664 of 5428
Median miles at test	7,066	10,652
MOT tests analysed	305	124,897
Most common failure	lighting and signalling	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.

"Vs comparable bikes" is the first-time pass rate minus the rate expected for each bike's own mix of age, mileage and test class, in percentage points: positive means better than comparable bikes. How this works.

Pass rate by test year

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

Test year	Vulcan Harrier	Yamaha YBR 125
2008	41.7%	71.1%
2009	52.5%	70.7%
2010	57.5%	71.4%
2011	46.3%	69.1%

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	Vulcan Harrier	Yamaha YBR 125
0k-10k miles	49.1%	76.8%
10k-20k miles	49.4%	67.4%

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

VULCAN HARRIER 49.2% pass · 305 tests YAMAHA YBR 125 71.0% pass · 125k tests

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