Bsa A50 vs Yamaha FZS600

The Bsa A50 passes its MOT first time more often than the Yamaha FZS600: 89.6% vs 82.6%, a 7.0-point lead.

MOT reliability, side by side

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

Metric	Bsa A50	Yamaha FZS600
First-time pass rate	89.6%	82.6%
Outright fail rate	3.7%	10.6%
Vs comparable bikes (age & mileage adjusted)	+5.9 pts	-0.8 pts
Engine size	500cc	599cc
Rank among all models	#1077 of 5428	#3052 of 5428
Median miles at test	13,154	21,612
MOT tests analysed	1,282	136,558
Most common failure	steering and suspension	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	Bsa A50	Yamaha FZS600
Brakes	1.2%	4.5%
Lights & signalling	1.4%	3.4%
Steering & suspension	1.3%	2.7%
Tyres & wheels	0.6%	2.9%
Structure & body	0.2%	1.1%
Drive system	0.3%	0.9%
Fuel & exhaust	0.1%	1.1%

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	Bsa A50	Yamaha FZS600
2010	89.1%	82.0%
2011	88.9%	81.1%
2012	89.1%	80.2%
2013	88.4%	81.3%
2014	90.0%	81.2%
2015	91.2%	81.1%
2016	93.4%	82.2%
2017	86.0%	82.0%

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	Bsa A50	Yamaha FZS600
0k-10k miles	90.0%	89.6%
10k-20k miles	90.4%	85.5%
20k-30k miles	87.8%	81.4%
30k-40k miles	87.7%	78.7%
40k-50k miles	88.3%	76.8%
50k-60k miles	96.2%	74.7%

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

Bsa A50 vs Yamaha FZS600 FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Bsa A50 or the Yamaha FZS600?

The Bsa A50 passes its MOT first time more often than the Yamaha FZS600: 89.6% vs 82.6%, a 7.0-point lead. Adjusted for age, mileage and test class, the Bsa A50 still comes out ahead: +5.9 points vs comparable bikes for the Bsa A50, -0.8 for the Yamaha FZS600. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Bsa A50 fail its MOT on most?

Lights & signalling: 1.4% of Bsa A50 MOT tests failed on it, then steering & suspension (1.3%).

What does the Yamaha FZS600 fail its MOT on most?

Brakes: 4.5% of Yamaha FZS600 MOT tests failed on it, then lights & signalling (3.4%).

Which holds up better at high mileage, the Bsa A50 or the Yamaha FZS600?

At 50k-60k miles the Bsa A50 passes first time more often: 96.2% for the Bsa A50 vs 74.7% for the Yamaha FZS600.

BSA A50 89.6% pass · 1,282 tests YAMAHA FZS600 82.6% pass · 137k tests

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