BIKERELIABILITY Reg check
League table/ KSR Moto Worx 125/vs Yamaha YBR 125
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

KSR Moto Worx 125 vs Yamaha YBR 125

The Yamaha YBR 125 passes its MOT first time more often than the KSR Moto Worx 125: 71.0% vs 64.3%, a 6.7-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric KSR Moto Worx 125 Yamaha YBR 125
First-time pass rate 64.3% 71.0%
Outright fail rate 25.5% 17.1%
Vs comparable bikes (age & mileage adjusted) -11.2 pts -1.1 pts
Engine size 125cc 124cc
Rank among all models #5044 of 5428 #4664 of 5428
Median miles at test 7,728 10,652
MOT tests analysed 1,387 124,897
Most common failure structure and attachments 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 KSR Moto Worx 125 Yamaha YBR 125
Lights & signalling 14.5% 8.5%
Steering & suspension 10.5% 6.5%
Structure & body 11.6% 3.8%
Brakes 7.8% 5.9%
Tyres & wheels 4.4% 4.4%
Drive system 1.4% 2.9%
Fuel & exhaust 0.1% 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 KSR Moto Worx 125 Yamaha YBR 125
2018 64.8% 72.0%
2019 66.5% 71.8%
2020 69.2% 73.4%
2021 60.6% 71.6%
2022 65.6% 71.3%
2023 57.5% 71.1%
2024 58.1% 70.9%
2025 59.2% 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 KSR Moto Worx 125 Yamaha YBR 125
0k-10k miles 68.4% 76.8%
10k-20k miles 57.7% 67.4%
20k-30k miles 49.4% 63.8%

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

KSR Moto Worx 125 vs Yamaha YBR 125 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the KSR Moto Worx 125 or the Yamaha YBR 125?

The Yamaha YBR 125 passes its MOT first time more often than the KSR Moto Worx 125: 71.0% vs 64.3%, a 6.7-point lead. Adjusted for age, mileage and test class, the Yamaha YBR 125 still comes out ahead: -11.2 points vs comparable bikes for the KSR Moto Worx 125, -1.1 for the Yamaha YBR 125. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the KSR Moto Worx 125 fail its MOT on most?

Lights & signalling: 14.5% of KSR Moto Worx 125 MOT tests failed on it, then structure & body (11.6%).

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%).

Which holds up better at high mileage, the KSR Moto Worx 125 or the Yamaha YBR 125?

At 20k-30k miles the Yamaha YBR 125 passes first time more often: 49.4% for the KSR Moto Worx 125 vs 63.8% for the Yamaha YBR 125.

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