BIKERELIABILITY Reg check
League table/ AJS/DD100E
Model report · 2005–2025

AJS DD100E

98cc Petrol Class 1
72.6%
first-time pass rate
20.3%
failed outright
3,217
median miles at test
197
MOT tests, 2005–2025
-6.4pp
vs expected · age & mileage

The pass rate is the MOT first-time pass: a roadworthiness check of the items an MOT covers (brakes, lights, tyres, steering, structure, emissions), not a full mechanical inspection of engine or gearbox internals. It is a reliability signal, not a complete measure of mechanical reliability. What this measures.

“vs expected” adjusts for age, mileage and test class, so a cherished classic and a hard-used commuter are compared fairly. How this works.

What fails on a DD100E

failure defects by component group · advisories excluded
Component group Share of defects Defects % of defects
lighting and signalling
69 43.7
steering and suspension
28 17.7
brakes
25 15.8
drive system
11 7
tyres and wheels
8 5.1
body and structure
6 3.8
Items Not Tested
3 1.9
fuel and exhaust
3 1.9
suspension
3 1.9
reg plates and vin
2 1.3

Defects recorded against failed normal tests, 2005–2025, grouped by DVSA inspection section. One test can record multiple defects.

How rivals compare

same type, similar capacity, high test volume

On first-time pass rate the DD100E beats 2 of its 4 closest rivals (YAMAHA YBR 125, HONDA C90, HONDA CG125).

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 DD100E.

Compare with any bike

rival not listed above? pick any model to see it head-to-head with the DD100E

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