BIKERELIABILITY Reg check
Head-to-head · 2005–2025

HARLEY-DAVIDSON XL 883L SPORTSTER vs TRIUMPH THUNDERBIRD

The HARLEY-DAVIDSON XL 883L SPORTSTER passes its MOT first time more often than the TRIUMPH THUNDERBIRD — 88.2% vs 87.8%, a 0.4-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric HARLEY-DAVIDSON XL 883L SPORTSTER TRIUMPH THUNDERBIRD
First-time pass rate 88.2% 87.8%
Outright fail rate 5.4% 6.2%
Median miles at test 7,980 13,106
MOT tests analysed 5,316 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.

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