Vincent Black Shadow vs Triumph Thunderbird

The Vincent Black Shadow passes its MOT first time more often than the Triumph Thunderbird: 94.0% vs 87.8%, a 6.2-point lead.

MOT reliability, side by side

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

Metric	Vincent Black Shadow	Triumph Thunderbird
First-time pass rate	94.0%	87.8%
Outright fail rate	1.2%	6.2%
Engine size	998cc	885cc
Rank among all models	#172 of 5428	#1669 of 5428
Median miles at test	13,531	13,106
MOT tests analysed	822	56,312
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.

What fails, side by side

share of each bike's MOT tests that failed on the component · lower is better

Component	Vincent Black Shadow	Triumph Thunderbird
Lights & signalling	0.7%	2.2%
Brakes	0.2%	2.0%
Tyres & wheels	0.1%	1.6%
Steering & suspension	0.2%	1.3%
Fuel & exhaust	0%	0.4%
Drive system	0.1%	0.2%
Structure & body	0%	0.3%

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	Vincent Black Shadow	Triumph Thunderbird
2006	96.3%	87.9%
2007	91.9%	87.4%
2008	96.0%	86.9%
2009	90.8%	86.1%
2010	93.6%	86.3%
2011	94.7%	86.1%
2012	91.6%	88.1%

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	Vincent Black Shadow	Triumph Thunderbird
0k-10k miles	94.5%	90.5%
10k-20k miles	94.6%	87.3%
20k-30k miles	92.2%	85.4%
30k-40k miles	93.9%	84.3%
40k-50k miles	90.9%	83.2%
50k-60k miles	92.0%	83.6%

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

Vincent Black Shadow vs Triumph Thunderbird FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Vincent Black Shadow or the Triumph Thunderbird?

The Vincent Black Shadow passes its MOT first time more often than the Triumph Thunderbird: 94.0% vs 87.8%, a 6.2-point lead. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Vincent Black Shadow fail its MOT on most?

Lights & signalling: 0.7% of Vincent Black Shadow MOT tests failed on it, then brakes (0.2%).

What does the Triumph Thunderbird fail its MOT on most?

Lights & signalling: 2.2% of Triumph Thunderbird MOT tests failed on it, then brakes (2.0%).

Which holds up better at high mileage, the Vincent Black Shadow or the Triumph Thunderbird?

At 50k-60k miles the Vincent Black Shadow passes first time more often: 92.0% for the Vincent Black Shadow vs 83.6% for the Triumph Thunderbird.

VINCENT BLACK SHADOW 94.0% pass · 822 tests TRIUMPH THUNDERBIRD 87.8% pass · 56.3k tests

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