Is this a joke?

If you mean fitting steel tyres to alloy wheels, I don't see why not. Is there a particular reason for going down this route (I ask as I have a half-started driving car may have some tube I could use for tyres, but I'm not sure if I do what I could use for wheels).

Neil

Fizzy, i think Joey is perhaps thinking of cutting a short length of a large diameter thick wall tube, rather than wrapping a piece of tube round a hub !!!!!

Cheers Derek

You would also need a different material for the centre bearing.
Potentially with reasonable use the outer rim will get stretched by effectively being continually cold rolled and become loose unless a hard steel is used and shrunk on. Perhaps you were thinking of cast alloy spokes. If just to avoid expensive castings or gettting large steel discs cut perhaps welded plate centres would do.

It's roughly right, but not the whole story.

The density of iron is about 7850kg/m^3, aluminium is about 2710kg/m^3, so as correctly stated aluminium is about a third as dense as steel.

A typical tensile strength for EN1A is 400MPa, for pure aluminium (1050) about 130MPa, depending upon temper. So pure aluminium is only a third of the strength of EN1A. However, pure aluminium (1050) is unlikely to be available in any form other than sheet, as it bends easily without cracking, but machines badly.

The inners of the wheels would most likely be made from an aluminium alloy. For a common aluminium alloy, 6082, with a mid-temper, tensile strength is around 260MPa, so more like two thirds the strength of steel. For an aircraft spec aluminium alloy, 7075 with a T6 temper, tensile strength is around 500MPa, so stronger than steel. If it wasn't then we'd make aeroplanes from steel as it would be cheaper.

Regards,

Andrew