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

Data as of: DVSA MOT results to 2025

Indian Motorcycle Scout Bobber vs Triumph Thunderbird

The Indian Motorcycle Scout Bobber passes its MOT first time more often than the Triumph Thunderbird: 90.2% vs 87.8%, a 2.4-point lead.

MOT reliability, side by side

first-time pass rate, outright fail rate and tests analysed · 2005–2025
Metric Indian Motorcycle Scout Bobber Triumph Thunderbird
First-time pass rate 90.2% 87.8%
Outright fail rate 4.0% 6.2%
Vs comparable bikes (age & mileage adjusted) +0.8 pts +2.1 pts
Engine size 1,133cc 885cc
Rank among all models #884 of 5428 #1669 of 5428
Median miles at test 3,985 13,106
MOT tests analysed 1,836 56,312
Most common failure lamps and reflectors 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 Indian Motorcycle Scout Bobber Triumph Thunderbird
Lights & signalling 1.9% 2.2%
Brakes 0.4% 2.0%
Tyres & wheels 0.4% 1.6%
Steering & suspension 0.5% 1.3%
Structure & body 0.7% 0.3%
Fuel & exhaust 0% 0.4%
Drive system 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 Indian Motorcycle Scout Bobber Triumph Thunderbird
2021 92.8% 88.2%
2022 88.0% 88.9%
2023 89.9% 90.5%
2024 90.5% 88.2%
2025 90.7% 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 Indian Motorcycle Scout Bobber Triumph Thunderbird
0k-10k miles 90.9% 90.5%
10k-20k miles 86.2% 87.3%

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

Indian Motorcycle Scout Bobber vs Triumph Thunderbird FAQ

answers computed from the data above · terms in the glossary

Which is more reliable, the Indian Motorcycle Scout Bobber or the Triumph Thunderbird?

The Indian Motorcycle Scout Bobber passes its MOT first time more often than the Triumph Thunderbird: 90.2% vs 87.8%, a 2.4-point lead. Adjusted for age, mileage and test class, the Triumph Thunderbird still comes out ahead: +0.8 points vs comparable bikes for the Indian Motorcycle Scout Bobber, +2.1 for the Triumph Thunderbird. An MOT checks roadworthiness items, not engine or gearbox internals.

What does the Indian Motorcycle Scout Bobber fail its MOT on most?

Lights & signalling: 1.9% of Indian Motorcycle Scout Bobber MOT tests failed on it, then structure & body (0.7%).

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%).

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