BIKERELIABILITY Reg check
Head-to-head · 2005–2025

Data as of: DVSA MOT results to 2025

Derbi Senda (restricted) vs Piaggio Zip

The Piaggio Zip passes its MOT first time more often than the Derbi Senda (restricted): 71.3% vs 46.7%, a 24.6-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Derbi Senda (restricted) Piaggio Zip
First-time pass rate 46.7% 71.3%
Outright fail rate 43.4% 20.4%
Vs comparable bikes (age & mileage adjusted) -23.8 pts -1.0 pts
Engine size 49cc 49cc
Rank among all models #5414 of 5428 #4631 of 5428
Median miles at test 11,351 8,882
MOT tests analysed 516 78,993
Most common failure lighting and signalling 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 Derbi Senda (restricted) Piaggio Zip
Lights & signalling 33.3% 11.9%
Steering & suspension 22.3% 9.2%
Brakes 18.2% 6.5%
Tyres & wheels 9.9% 4.0%
Drive system 9.3% 0.0%
Fuel & exhaust 5.6% 2.5%
Structure & body 4.8% 1.6%

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 Derbi Senda (restricted) Piaggio Zip
2006 49.6% 73.7%
2007 42.7% 71.0%
2008 33.9% 72.4%
2009 35.1% 70.0%

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 Derbi Senda (restricted) Piaggio Zip
0k-10k miles 50.5% 75.2%
10k-20k miles 43.3% 66.7%
20k-30k miles 46.9% 64.4%

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

Derbi Senda (restricted) vs Piaggio Zip FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Derbi Senda (restricted) or the Piaggio Zip?

The Piaggio Zip passes its MOT first time more often than the Derbi Senda (restricted): 71.3% vs 46.7%, a 24.6-point lead. Adjusted for age, mileage and test class, the Piaggio Zip still comes out ahead: -23.8 points vs comparable bikes for the Derbi Senda (restricted), -1.0 for the Piaggio Zip. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Derbi Senda (restricted) fail its MOT on most?

Lights & signalling: 33.3% of Derbi Senda (restricted) MOT tests failed on it, then steering & suspension (22.3%).

What does the Piaggio Zip fail its MOT on most?

Lights & signalling: 11.9% of Piaggio Zip MOT tests failed on it, then steering & suspension (9.2%).

Which holds up better at high mileage, the Derbi Senda (restricted) or the Piaggio Zip?

At 20k-30k miles the Piaggio Zip passes first time more often: 46.9% for the Derbi Senda (restricted) vs 64.4% for the Piaggio Zip.

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