WK Bikes BD vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the WK Bikes BD: 71.0% vs 62.1%, a 8.9-point lead.

MOT reliability, side by side

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

Metric	WK Bikes BD	Yamaha YBR 125
First-time pass rate	62.1%	71.0%
Outright fail rate	26.7%	17.1%
Vs comparable bikes (age & mileage adjusted)	-17.2 pts	-1.1 pts
Engine size	125cc	124cc
Rank among all models	#5143 of 5428	#4664 of 5428
Median miles at test	3,111	10,652
MOT tests analysed	206	124,897
Most common failure	lamps and reflectors	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	WK Bikes BD	Yamaha YBR 125
2019	70.6%	71.8%
2020	62.5%	73.4%
2021	52.9%	71.6%

Each year mixes bikes of different ages, so a fleet that is getting older tends to slip.

WK BIKES BD 62.1% pass · 206 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.