BIKERELIABILITY Reg check
League table/ ARIEL/SQUARE 4
Model report · 2005–2025

ARIEL SQUARE 4

1000cc Petrol Class 2
93.6%
first-time pass rate
0.8%
failed outright
5,713
median miles at test
125
MOT tests, 2005–2025

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.

What fails on a SQUARE 4

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects
brakes
1 100

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 SQUARE 4 beats 4 of its 4 closest rivals (BMW R1200, BMW R1150, TRIUMPH SPRINT).

BMW R1200 92.9% pass · 299k tests Compare head-to-head →
BMW R1150 88.5% pass · 171k tests Compare head-to-head →
TRIUMPH SPRINT 85.6% pass · 133k tests Compare head-to-head →
SUZUKI GSF1200 82.4% pass · 97.6k tests Compare head-to-head →

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 SQUARE 4.

Compare with any bike

rival not listed above? pick any model to see it head-to-head with the Square 4

More ARIEL models

other ARIEL bikes ranked by MOT pass rate
ARIEL ARROW 93.7% pass · 1,615 tests
ARIEL RED HUNTER 92.2% pass · 1,422 tests
ARIEL LEADER 92.7% pass · 1,135 tests
ARIEL HUNTMASTER 94.1% pass · 631 tests
ARIEL SQUARE FOUR 91.4% pass · 555 tests
ARIEL NH 92.4% pass · 342 tests

See all ARIEL models →

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