Ajs DD 125 E 08 vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the Ajs DD 125 E 08: 71.0% vs 67.3%, a 3.7-point lead.

MOT reliability, side by side

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

Metric	Ajs DD 125 E 08	Yamaha YBR 125
First-time pass rate	67.3%	71.0%
Outright fail rate	20.3%	17.1%
Vs comparable bikes (age & mileage adjusted)	-8.1 pts	-1.1 pts
Engine size	125cc	124cc
Rank among all models	#4895 of 5428	#4664 of 5428
Median miles at test	5,256	10,652
MOT tests analysed	1,468	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	Ajs DD 125 E 08	Yamaha YBR 125
Lights & signalling	12.6%	8.5%
Brakes	8.0%	5.9%
Steering & suspension	7.0%	6.5%
Tyres & wheels	3.9%	4.4%
Structure & body	3.7%	3.8%
Drive system	3.8%	2.9%
Fuel & exhaust	1.0%	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	Ajs DD 125 E 08	Yamaha YBR 125
2018	62.0%	72.0%
2019	63.6%	71.8%
2020	71.4%	73.4%
2021	67.1%	71.6%
2022	55.4%	71.3%
2023	63.5%	71.1%
2024	74.3%	70.9%
2025	83.9%	71.2%

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	Ajs DD 125 E 08	Yamaha YBR 125
0k-10k miles	68.9%	76.8%
10k-20k miles	60.9%	67.4%

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

Ajs DD 125 E 08 vs Yamaha YBR 125 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Ajs DD 125 E 08 or the Yamaha YBR 125?

The Yamaha YBR 125 passes its MOT first time more often than the Ajs DD 125 E 08: 71.0% vs 67.3%, a 3.7-point lead. Adjusted for age, mileage and test class, the Yamaha YBR 125 still comes out ahead: -8.1 points vs comparable bikes for the Ajs DD 125 E 08, -1.1 for the Yamaha YBR 125. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Ajs DD 125 E 08 fail its MOT on most?

Lights & signalling: 12.6% of Ajs DD 125 E 08 MOT tests failed on it, then brakes (8.0%).

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%).

AJS DD 125 E 08 67.3% pass · 1,468 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.