Mutt Fat Sabbath 125 vs Gilera Runner

The Gilera Runner passes its MOT first time more often than the Mutt Fat Sabbath 125: 70.8% vs 69.7%, a 1.1-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025

Metric	Mutt Fat Sabbath 125	Gilera Runner
First-time pass rate	69.7%	70.8%
Outright fail rate	18.6%	21.5%
Vs comparable bikes (age & mileage adjusted)	-8.1 pts	-0.7 pts
Engine size	125cc	124cc
Rank among all models	#4760 of 5428	#4675 of 5428
Median miles at test	3,044	11,381
MOT tests analysed	591	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	Mutt Fat Sabbath 125	Gilera Runner
Lights & signalling	13.0%	12.3%
Steering & suspension	3.2%	10.6%
Brakes	6.3%	7.2%
Structure & body	5.2%	2.0%
Tyres & wheels	0.2%	5.1%
Fuel & exhaust	0%	2.6%

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	Mutt Fat Sabbath 125	Gilera Runner
2022	66.7%	80.5%
2023	72.4%	81.3%
2024	72.0%	84.0%
2025	67.2%	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	Mutt Fat Sabbath 125	Gilera Runner
0k-10k miles	70.3%	76.2%
10k-20k miles	59.6%	67.5%

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

Mutt Fat Sabbath 125 vs Gilera Runner FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Mutt Fat Sabbath 125 or the Gilera Runner?

The Gilera Runner passes its MOT first time more often than the Mutt Fat Sabbath 125: 70.8% vs 69.7%, a 1.1-point lead. Adjusted for age, mileage and test class, the Gilera Runner still comes out ahead: -8.1 points vs comparable bikes for the Mutt Fat Sabbath 125, -0.7 for the Gilera Runner. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Mutt Fat Sabbath 125 fail its MOT on most?

Lights & signalling: 13.0% of Mutt Fat Sabbath 125 MOT tests failed on it, then brakes (6.3%).

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%).

MUTT FAT SABBATH 125 69.7% pass · 591 tests GILERA RUNNER 70.8% pass · 69.9k tests

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