Harley-Davidson XR 1200 X Sportster 11 vs Triumph Thunderbird

The Harley-Davidson XR 1200 X Sportster 11 passes its MOT first time more often than the Triumph Thunderbird: 94.4% vs 87.8%, a 6.6-point lead.

MOT reliability, side by side

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

Metric	Harley-Davidson XR 1200 X Sportster 11	Triumph Thunderbird
First-time pass rate	94.4%	87.8%
Outright fail rate	2.2%	6.2%
Vs comparable bikes (age & mileage adjusted)	+6.6 pts	+2.1 pts
Engine size	1,202cc	885cc
Rank among all models	#126 of 5428	#1669 of 5428
Median miles at test	7,320	13,106
MOT tests analysed	232	56,312
Most common failure	structure and attachments	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.

Pass rate by mileage

first-time MOT pass rate by miles on the clock at test

Mileage	Harley-Davidson XR 1200 X Sportster 11	Triumph Thunderbird
0k-10k miles	94.2%	90.5%
10k-20k miles	94.8%	87.3%

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

HARLEY-DAVIDSON XR 1200 X SPORTSTER 11 94.4% pass · 232 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.