Better BT 125-20 vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the Better BT 125-20: 71.0% vs 55.3%, a 15.7-point lead.

MOT reliability, side by side

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

Metric	Better BT 125-20	Yamaha YBR 125
First-time pass rate	55.3%	71.0%
Outright fail rate	30.1%	17.1%
Vs comparable bikes (age & mileage adjusted)	-20.3 pts	-1.1 pts
Engine size	125cc	124cc
Rank among all models	#5335 of 5428	#4664 of 5428
Median miles at test	4,245	10,652
MOT tests analysed	976	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.

What fails, side by side

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

Component	Better BT 125-20	Yamaha YBR 125
Lights & signalling	19.2%	8.5%
Steering & suspension	13.8%	6.5%
Brakes	11.0%	5.9%
Tyres & wheels	6.7%	4.4%
Structure & body	7.2%	3.8%
Drive system	5.8%	2.9%
Fuel & exhaust	2.7%	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	Better BT 125-20	Yamaha YBR 125
2009	54.9%	70.7%
2010	59.3%	71.4%
2011	58.9%	69.1%
2012	48.3%	69.1%
2013	52.9%	69.5%
2014	44.4%	70.0%
2015	52.8%	71.2%
2016	48.8%	71.3%

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	Better BT 125-20	Yamaha YBR 125
0k-10k miles	57.7%	76.8%
10k-20k miles	44.1%	67.4%

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

Better BT 125-20 vs Yamaha YBR 125 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Better BT 125-20 or the Yamaha YBR 125?

The Yamaha YBR 125 passes its MOT first time more often than the Better BT 125-20: 71.0% vs 55.3%, a 15.7-point lead. Adjusted for age, mileage and test class, the Yamaha YBR 125 still comes out ahead: -20.3 points vs comparable bikes for the Better BT 125-20, -1.1 for the Yamaha YBR 125. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Better BT 125-20 fail its MOT on most?

Lights & signalling: 19.2% of Better BT 125-20 MOT tests failed on it, then steering & suspension (13.8%).

What does the Yamaha YBR 125 fail its MOT on most?

Lights & signalling: 8.5% of Yamaha YBR 125 MOT tests failed on it, then steering & suspension (6.5%).

BETTER BT 125-20 55.3% pass · 976 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.