BIKERELIABILITY Reg check
League table/ DERBI/TERRA 125
Model report · 2005–2025

DERBI TERRA 125

124cc Petrol Class 1
#4875 of 5428 overall #5 of 19 DERBIs #451 of 734 commuter bikes
67.7%
first-time pass rate
24.3%
failed outright
6,802
median miles at test
613
MOT tests, 2005–2025
-5.7pp
vs expected · age & mileage

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.

“vs expected” adjusts for age, mileage and test class, so a cherished classic and a hard-used commuter are compared fairly. How this works.

Pass rate over time

first-time pass rate by test year · 2012–2017

The TERRA 125's first-time pass rate has held steady since 2012 (66.1% → 65.5%).

56%68%80%2012: 66.1% pass (56 tests)2013: 76.3% pass (80 tests)2014: 60.2% pass (88 tests)2015: 63.3% pass (79 tests)2016: 72.1% pass (61 tests)2017: 65.5% pass (58 tests)20122017

What fails on a TERRA 125

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects vs all bikes
brakes
104 24.5 2.7×
lighting and signalling
104 24.5 2.4×
steering and suspension
72 16.9 2.9×
drive system
47 11.1 8.8×
lamps and reflectors
30 7.1 1.9×
structure and attachments
19 4.5 2.1×
tyres and wheels
18 4.2 1.2×
suspension
16 3.8 3.1×
fuel and exhaust
9 2.1 1.9×
driving controls
6 1.4 3.5×

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

same type, similar capacity, high test volume

On first-time pass rate the TERRA 125 beats 0 of its 4 closest rivals (YAMAHA YBR 125, HONDA CG125, HONDA CBF125).

YAMAHA YBR 125 71.0% pass · 125k tests Compare head-to-head →
HONDA CG125 72.2% pass · 89.3k tests Compare head-to-head →
HONDA CBF125 73.3% pass · 84.4k tests Compare head-to-head →
GILERA RUNNER 70.8% pass · 69.9k 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 TERRA 125.

Compare with any bike

rival not listed above? pick any model to see it head-to-head with the Terra 125

More DERBI models

other DERBI bikes ranked by MOT pass rate
DERBI SENDA 55.0% pass · 9,050 tests
DERBI GPR50-R 53.4% pass · 1,901 tests
DERBI GPR 50 54.7% pass · 1,847 tests
DERBI ATLANTIS 73.4% pass · 1,505 tests
DERBI PREDATOR 66.3% pass · 1,298 tests
DERBI SENDA SM 51.1% pass · 1,013 tests

See all DERBI models →

Pass rate by registration year

how each model-year cohort fares · registration year from first use date

Best year to buy used: 2008 (70.8% pass). Weakest: 2011 (55.7%).

53%63%74%2008: 70.8% pass (192 tests)2009: 68.3% pass (180 tests)2010: 68.9% pass (148 tests)2011: 55.7% pass (61 tests)200820102011

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.

DERBI TERRA 125 FAQ

answers computed from the data above · terms in the glossary

Is the DERBI TERRA 125 reliable?

The DERBI TERRA 125 is less reliable than average for its class: 67.7% of its 613 MOT tests (2005–2025) passed first time, against a class average of 73.4%. That ranks it #4875 of 5428 models.

What does a TERRA 125 fail its MOT on most?

brakes — 24% of all defects recorded against failed TERRA 125 tests.

What is the best year of TERRA 125 to buy used?

By first-time pass rate, 2008-registered examples do best (70.8%) and 2011 worst (55.7%). Condition and history still trump the year.

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