Pgo T-Rex vs Yamaha YBR 125

The Pgo T-Rex passes its MOT first time more often than the Yamaha YBR 125: 76.5% vs 71.0%, a 5.5-point lead.

MOT reliability, side by side

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

Metric	Pgo T-Rex	Yamaha YBR 125
First-time pass rate	76.5%	71.0%
Outright fail rate	16.7%	17.1%
Vs comparable bikes (age & mileage adjusted)	+5.7 pts	-1.1 pts
Engine size	124cc	124cc
Rank among all models	#4125 of 5428	#4664 of 5428
Median miles at test	12,691	10,652
MOT tests analysed	1,219	124,897
Most common failure	lighting and signalling	brakes

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	Pgo T-Rex	Yamaha YBR 125
Lights & signalling	8.5%	8.5%
Brakes	6.8%	5.9%
Tyres & wheels	5.7%	4.4%
Steering & suspension	3.5%	6.5%
Structure & body	1.0%	3.8%
Drive system	0%	2.9%
Fuel & exhaust	1.9%	0.6%

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	Pgo T-Rex	Yamaha YBR 125
2012	75.5%	69.1%
2013	79.4%	69.5%
2014	75.0%	70.0%
2015	77.8%	71.2%
2016	69.1%	71.3%
2017	76.6%	70.7%
2018	78.9%	72.0%
2019	70.0%	71.8%

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	Pgo T-Rex	Yamaha YBR 125
0k-10k miles	85.9%	76.8%
10k-20k miles	72.3%	67.4%
20k-30k miles	69.0%	63.8%
30k-40k miles	67.9%	62.2%

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

Pgo T-Rex vs Yamaha YBR 125 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Pgo T-Rex or the Yamaha YBR 125?

The Pgo T-Rex passes its MOT first time more often than the Yamaha YBR 125: 76.5% vs 71.0%, a 5.5-point lead. Adjusted for age, mileage and test class, the Pgo T-Rex still comes out ahead: +5.7 points vs comparable bikes for the Pgo T-Rex, -1.1 for the Yamaha YBR 125. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Pgo T-Rex fail its MOT on most?

Lights & signalling: 8.5% of Pgo T-Rex MOT tests failed on it, then brakes (6.8%).

What does the Yamaha YBR 125 fail its MOT on most?

Lights & signalling: 8.5% of Yamaha YBR 125 MOT tests failed on it, then steering & suspension (6.5%).

Which holds up better at high mileage, the Pgo T-Rex or the Yamaha YBR 125?

At 30k-40k miles the Pgo T-Rex passes first time more often: 67.9% for the Pgo T-Rex vs 62.2% for the Yamaha YBR 125.

PGO T-REX 76.5% pass · 1,219 tests YAMAHA YBR 125 71.0% pass · 125k tests

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