Harley-Davidson 1200 Sport vs Triumph Thunderbird

The Triumph Thunderbird passes its MOT first time more often than the Harley-Davidson 1200 Sport: 87.8% vs 86.0%, a 1.8-point lead.

MOT reliability, side by side

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

Metric	Harley-Davidson 1200 Sport	Triumph Thunderbird
First-time pass rate	86.0%	87.8%
Outright fail rate	6.8%	6.2%
Vs comparable bikes (age & mileage adjusted)	+0.5 pts	+2.1 pts
Engine size	1,200cc	885cc
Rank among all models	#2197 of 5428	#1669 of 5428
Median miles at test	12,506	13,106
MOT tests analysed	2,878	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.

"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	Harley-Davidson 1200 Sport	Triumph Thunderbird
Lights & signalling	3.5%	2.2%
Brakes	2.0%	2.0%
Tyres & wheels	1.6%	1.6%
Steering & suspension	0.9%	1.3%
Fuel & exhaust	0.6%	0.4%
Structure & body	0.2%	0.3%
Drive system	0.0%	0.2%

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	Harley-Davidson 1200 Sport	Triumph Thunderbird
2018	87.3%	87.8%
2019	88.7%	87.7%
2020	90.1%	88.8%
2021	89.9%	88.2%
2022	84.7%	88.9%
2023	87.1%	90.5%
2024	87.0%	88.2%
2025	85.3%	89.5%

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	Harley-Davidson 1200 Sport	Triumph Thunderbird
0k-10k miles	85.5%	90.5%
10k-20k miles	86.7%	87.3%
20k-30k miles	84.1%	85.4%
30k-40k miles	85.5%	84.3%
40k-50k miles	88.7%	83.2%
50k-60k miles	87.2%	83.6%

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

Harley-Davidson 1200 Sport vs Triumph Thunderbird FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Harley-Davidson 1200 Sport or the Triumph Thunderbird?

The Triumph Thunderbird passes its MOT first time more often than the Harley-Davidson 1200 Sport: 87.8% vs 86.0%, a 1.8-point lead. Adjusted for age, mileage and test class, the Triumph Thunderbird still comes out ahead: +0.5 points vs comparable bikes for the Harley-Davidson 1200 Sport, +2.1 for the Triumph Thunderbird. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Harley-Davidson 1200 Sport fail its MOT on most?

Lights & signalling: 3.5% of Harley-Davidson 1200 Sport MOT tests failed on it, then brakes (2.0%).

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 Harley-Davidson 1200 Sport or the Triumph Thunderbird?

At 50k-60k miles the Harley-Davidson 1200 Sport passes first time more often: 87.2% for the Harley-Davidson 1200 Sport vs 83.6% for the Triumph Thunderbird.

HARLEY-DAVIDSON 1200 SPORT 86.0% pass · 2,878 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.