WK BIKES SX 125

125cc Petrol Class 1

#4818 of 5426 overall #5 of 7 WK BIKESs #425 of 734 commuter bikes

68.6%

first-time pass rate

21.6%

failed outright

5,614

median miles at test

236

MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2024–2025

The SX 125's first-time pass rate has risen 6.7 points since 2024, 63.9% to 70.6%.

What fails on a SX 125

failure defects by component group · advisories excluded

Component group	Defects	% of defects
brakes	47	29.2
lamps and reflectors	45	28
suspension	38	23.6
steering	15	9.3
tyres	9	5.6
structure and attachments	5	3.1
audible warning (Horn)	1	0.6
Identification of the vehicle	1	0.6

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 SX 125 beats 0 of its 4 closest rivals (YAMAHA YBR 125, HONDA CG125, HONDA CBF125).

YAMAHA YBR 125 71.0% pass · 125k tests HONDA CG125 72.2% pass · 89.3k tests HONDA CBF125 73.3% pass · 84.4k tests GILERA RUNNER 70.8% pass · 69.9k tests

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 SX 125.

Pass rate by registration year

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

Best year to buy used: 2022 (72.5% pass). Weakest: 2021 (63.8%).

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.