Bsa D1 vs Yamaha YBR 125

The Bsa D1 passes its MOT first time more often than the Yamaha YBR 125: 87.5% vs 71.0%, a 16.5-point lead.

MOT reliability, side by side

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

Metric	Bsa D1	Yamaha YBR 125
First-time pass rate	87.5%	71.0%
Outright fail rate	5.4%	17.1%
Engine size	125cc	124cc
Rank among all models	#1750 of 5428	#4664 of 5428
Median miles at test	11,600	10,652
MOT tests analysed	391	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.

Pass rate by test year

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

Test year	Bsa D1	Yamaha YBR 125
2008	83.3%	71.1%
2009	83.7%	70.7%
2010	85.4%	71.4%
2011	92.9%	69.1%
2012	84.2%	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	Bsa D1	Yamaha YBR 125
0k-10k miles	92.3%	76.8%
10k-20k miles	90.5%	67.4%
20k-30k miles	76.8%	63.8%
30k-40k miles	84.8%	62.2%

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

BSA D1 87.5% pass · 391 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.