74mm Front Hubs - WHY ?

fatbee
fatbee Posts: 581
edited July 2008 in Workshop
This is probably a stupid question (my speciality) and may've been covered before on here (apologies if either or both is the case,) but . . .

Why do folding bikes like Bromptons and some Dahons have 74mm OLD front hubs instead of 100mm like normal? I mean it's not like you'd bang your toes on the front forks because they stuck out an extra 13mm each side to make room for a regular unit. Or is it?