BIKERELIABILITY Reg check
League table/ Ajs JS/vs Gilera Runner
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Ajs JS vs Gilera Runner

The Ajs JS passes its MOT first time more often than the Gilera Runner: 71.2% vs 70.8%, a 0.4-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Ajs JS Gilera Runner
First-time pass rate 71.2% 70.8%
Outright fail rate 20.2% 21.5%
Vs comparable bikes (age & mileage adjusted) -1.4 pts -0.7 pts
Engine size 124cc 124cc
Rank among all models #4640 of 5428 #4675 of 5428
Median miles at test 9,562 11,381
MOT tests analysed 674 69,850
Most common failure lamps and reflectors lighting and signalling

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 Ajs JS Gilera Runner
Lights & signalling 10.5% 12.3%
Steering & suspension 7.3% 10.6%
Brakes 7.6% 7.2%
Tyres & wheels 4.7% 5.1%
Structure & body 6.4% 2.0%
Fuel & exhaust 0% 2.6%
Drive system 1.0% 0.0%

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 Ajs JS Gilera Runner
2018 68.0% 77.2%
2019 73.3% 77.0%
2020 64.5% 75.8%
2021 79.1% 79.1%
2022 78.9% 80.5%
2023 60.6% 81.3%
2024 76.5% 84.0%
2025 79.5% 85.5%

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 Ajs JS Gilera Runner
0k-10k miles 75.4% 76.2%
10k-20k miles 67.5% 67.5%
20k-30k miles 60.0% 65.4%

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

Ajs JS vs Gilera Runner FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Ajs JS or the Gilera Runner?

The Ajs JS passes its MOT first time more often than the Gilera Runner: 71.2% vs 70.8%, a 0.4-point lead. Adjusted for age, mileage and test class the two are level (-1.4 vs -0.7 points against comparable bikes), so the raw gap is mostly down to how old and how used each fleet is. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Ajs JS fail its MOT on most?

Lights & signalling: 10.5% of Ajs JS MOT tests failed on it, then brakes (7.6%).

What does the Gilera Runner fail its MOT on most?

Lights & signalling: 12.3% of Gilera Runner MOT tests failed on it, then steering & suspension (10.6%).

Which holds up better at high mileage, the Ajs JS or the Gilera Runner?

At 20k-30k miles the Gilera Runner passes first time more often: 60.0% for the Ajs JS vs 65.4% for the Gilera Runner.

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