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.
Pass rate over time
The LEADER's first-time pass rate has risen 4.5 points since 2006, 89.2% to 93.7%.
Pass rate by mileage
A low-mileage LEADER passes first time 93.3% of the time; by 50k that's 92.7%.
First-time pass rate by odometer reading at test, 10,000-mile bands for this model. Mileage is the strongest reliability signal. See the full curve.
What fails on a LEADER
| Component group | Share of defects | Defects | % of defects | vs all bikes |
|---|---|---|---|---|
| lighting and signalling |
|
23 | 30.7 | 0.2× |
| brakes |
|
20 | 26.7 | 0.3× |
| steering and suspension |
|
17 | 22.7 | 0.4× |
| tyres and wheels |
|
6 | 8 | 0.3× |
| fuel and exhaust |
|
4 | 5.3 | 0.3× |
| drive system |
|
3 | 4 | 0.2× |
| Items Not Tested |
|
1 | 1.3 | 1.0× |
| body and structure |
|
1 | 1.3 | 0.2× |
Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects. "vs all bikes" is how often this model's tests record a defect in the group, as a multiple of the all-bike rate.
How rivals compare
On first-time pass rate the LEADER beats 4 of its 4 closest rivals (PIAGGIO PX 200 E, PIAGGIO X9, LAMBRETTA GP200).
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 LEADER.
Compare with any bike
More ARIEL models
Pass rate by registration year
Best year to buy used: 1963 (96.5% pass). Weakest: 1971 (87.5%).
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.
ARIEL LEADER FAQ
Is the ARIEL LEADER reliable?
The ARIEL LEADER is more reliable than average for its class: 92.7% of its 1,135 MOT tests (2005–2025) passed first time, against a class average of 84.9%. That ranks it #344 of 5428 models.
What does a LEADER fail its MOT on most?
lighting and signalling — 31% of all defects recorded against failed LEADER tests.
What is the best year of LEADER to buy used?
By first-time pass rate, 1963-registered examples do best (96.5%) and 1971 worst (87.5%). Condition and history still trump the year.
How many miles will a LEADER last?
The median LEADER shows 15,045 miles at test, and examples around 50k miles still pass 92.7% of the time — mileage alone rarely kills one.
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