Drunken Bungle Whore

OK - I know this sounds like a silly question, but PLEASE don't move me to Muppet as I'd actually quite like a serious answer.

I spend my life working with HGV/ Artic drivers as well as many, MANY hours on the motorway -and my question is this:

Why do the middles of all the wheels on lorries stick in - except for the ones on the cab - which stick out? It doesn't seem to have anything to do with locking wheel nuts etc.

Can't seem to find anyone around here who knows - all sensible answers gratefully received!

S.B.

Rear wheels : inside one sticks out outside one sticks in if you see what i mean so the rims meet so they bolt together on the hubs Like this ][ or sort of

hail-hail

The front wheels are single wheels and so the wheel sticks out. Rear wheels are usually two wheels stuck together hence the wheels stick in. simple really.

hail-hail

just beat me to it

S.B.

BOB.T

Could be wrong but....with the massive offset you could keep the halfshafts (axle) shorter and make them less prone to twisting with all the torque, probably