BIKERELIABILITY Reg check
Model report · 2005–2025

WK BIKES 125

124cc Petrol Class 1
#5340 of 5428 overall #7 of 7 WK BIKESs #693 of 734 commuter bikes
54.9%
first-time pass rate
35.9%
failed outright
4,229
median miles at test
446
MOT tests, 2005–2025
-21.4pp
vs expected · age & mileage

The pass rate is the MOT first-time pass: a roadworthiness check of the items an MOT covers (brakes, lights, tyres, steering, structure, emissions), not a full mechanical inspection of engine or gearbox internals. It is a reliability signal, not a complete measure of mechanical reliability. What this measures.

“vs expected” adjusts for age, mileage and test class, so a cherished classic and a hard-used commuter are compared fairly. How this works.

Pass rate over time

first-time pass rate by test year · 2017–2023

The 125's first-time pass rate has risen 11.3 points since 2017, 56.4% to 67.7%.

44%58%72%2017: 56.4% pass (110 tests)2018: 57.7% pass (71 tests)2019: 49.2% pass (59 tests)2020: 58.9% pass (56 tests)2021: 49.1% pass (53 tests)2022: 63.3% pass (30 tests)2023: 67.7% pass (31 tests)20172023

What fails on a 125

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects
structure and attachments
99 19.2
lamps and reflectors
94 18.3
brakes
89 17.3
suspension
62 12
steering
44 8.5
steering and suspension
44 8.5
lighting and signalling
39 7.6
body and structure
17 3.3
drive system
14 2.7
tyres
13 2.5

Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects.

How rivals compare

same type, similar capacity, high test volume

On first-time pass rate the 125 beats 0 of its 4 closest rivals (YAMAHA YBR 125, HONDA CG125, HONDA CBF125).

Rivals share this bike's type and sit within ±30% of its engine capacity, ≥ 5,000 tests. Card colour = better/worse first-time pass rate than the 125.

Compare with any bike

rival not listed above? pick any model to see it head-to-head with the 125

Pass rate by registration year

how each model-year cohort fares · registration year from first use date

Best year to buy used: 2014 (55.8% pass). Weakest: 2013 (54.1%).

53%55%57%2013: 54.1% pass (109 tests)2014: 55.8% pass (233 tests)2015: 54.8% pass (62 tests)201320142015

First-time pass rate by the year each bike was first registered (cohorts with ≥ 50 tests). Older cohorts are survivors: the worst examples have already left the road, which tends to lift the earliest years.

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Free to embed on your site, blog or forum — a live WK Bikes 125 reliability card that stays up to date and links back here. More on the free API page.