BIKERELIABILITY
MOT DATA · GREAT BRITAIN · 2005–2025
League table/ HARLEY-DAVIDSON/FXDF FAT BOB 1584 11
Model report · 2005–2025

HARLEY-DAVIDSON FXDF FAT BOB 1584 11

1584cc Petrol Class 2
87.9%
first-time pass rate
4.4%
failed outright
10,300
median miles at test
1,149
MOT tests, 2005–2025

Pass rate over time

first-time pass rate by test year · 2014–2025

The FXDF FAT BOB 1584 11's first-time pass rate has risen 9.8 points since 2014, 83.5% to 93.3%.

78%87%96%2014: 83.5% pass (133 tests)2015: 89.6% pass (125 tests)2016: 91.8% pass (122 tests)2017: 85.0% pass (113 tests)2018: 81.3% pass (80 tests)2019: 84.7% pass (85 tests)2020: 90.8% pass (65 tests)2021: 92.7% pass (96 tests)2022: 87.2% pass (86 tests)2023: 89.7% pass (87 tests)2024: 87.7% pass (65 tests)2025: 93.3% pass (75 tests)20142025

Pass rate by mileage

how the FXDF FAT BOB 1584 11's first-time pass rate falls with the odometer · class average 84.9%

A low-mileage FXDF FAT BOB 1584 11 passes first time 89.4% of the time; by 30k that's 76.5%.

74%83%92%0k: 89.4% pass (559 tests)10k: 87.2% pass (423 tests)20k: 86.9% pass (122 tests)30k: 76.5% pass (34 tests)0k20k30k

First-time pass rate by odometer reading at test, 10,000-mile bands for this model. Mileage is the strongest reliability signal. See the full curve.

What fails on a FXDF FAT BOB 1584 11

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects vs all bikes
lighting and signalling
22 26.8 0.3×
lamps and reflectors
19 23.2 0.9×
brakes
17 20.7 0.3×
tyres and wheels
5 6.1 0.2×
Identification of the vehicle
4 4.9 1.5×
reg plates and vin
4 4.9 0.6×
steering and suspension
3 3.7 0.1×
suspension
3 3.7 0.4×
tyres
3 3.7 0.3×
structure and attachments
2 2.4 0.3×

Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects. "vs all bikes" is how often this model's tests record a defect in the group, as a multiple of the all-bike rate.

How rivals compare

same type, similar capacity, high test volume

On first-time pass rate the FXDF FAT BOB 1584 11 beats 0 of its 4 closest rivals (HARLEY-DAVIDSON FLSTF, HARLEY-DAVIDSON FLSTC, HARLEY-DAVIDSON XL1200C).

Rivals share this bike's type and sit within ±30% of its engine capacity, ≥ 5,000 tests. Card colour = better/worse first-time pass rate than the FXDF FAT BOB 1584 11.

Pass rate by registration year

how each model-year cohort fares · registration year from first use date

Best year to buy used: 2010 (88.6% pass). Weakest: 2011 (87.6%).

87%88%89%2010: 88.6% pass (202 tests)2011: 87.6% pass (926 tests)20102011

First-time pass rate by the year each bike was first registered (cohorts with ≥ 50 tests). Older cohorts are survivors: the worst examples have already left the road, which tends to lift the earliest years.

HARLEY-DAVIDSON FXDF FAT BOB 1584 11 FAQ

answers computed from the data above · terms in the glossary

Is the HARLEY-DAVIDSON FXDF FAT BOB 1584 11 reliable?

The HARLEY-DAVIDSON FXDF FAT BOB 1584 11 is more reliable than average for its class: 87.9% of its 1,149 MOT tests (2005–2025) passed first time, against a class average of 84.9%. That ranks it #1639 of 5426 models.

What does a FXDF FAT BOB 1584 11 fail its MOT on most?

lighting and signalling — 27% of all defects recorded against failed FXDF FAT BOB 1584 11 tests.

How many miles will a FXDF FAT BOB 1584 11 last?

The median FXDF FAT BOB 1584 11 shows 10,300 miles at test, and examples around 30k miles still pass 76.5% of the time — mileage alone rarely kills one.