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beaded edge rims... in alloy?
Posted: Fri May 12, 2023 9:03 am
by Anthony Bennett
Howdy blokes
A thought occurred to me while pondering laced wire wheels, that while there are new beaded edge rims available, would aluminium be a reasonable choice to make them from?
We always plate original rims with a silver cad finish as they used to be, but anodised alloy would arguably be an even longer lasting finish, assuming you don't wreck them with tyre levers.
I realise unsprung weight isn't the be all and end all in T Ford motoring, but it certainly does help with bicycles, they've had alloy rims forever.
Cheers
Re: beaded edge rims... in alloy?
Posted: Fri May 12, 2023 10:53 am
by Humblej
If I can remember my metallurgy class from college, steel has a modulus of elasticity of around 200 GPa, where as aluminum has a modulus of elasticity of around 70 GPa. So to duplicate the properties of a steel rim with an aluminum rim, the aluminum rim would have to be about 3 times thicker than the steel rim.
Re: beaded edge rims... in alloy?
Posted: Fri May 12, 2023 11:33 am
by ModelTWoods
Humblej wrote: ↑Fri May 12, 2023 10:53 am
If I can remember my metallurgy class from college, steel has a modulus of elasticity of around 200 GPa, where as aluminum has a modulus of elasticity of around 70 GPa. So to duplicate the properties of a steel rim with an aluminum rim, the aluminum rim would have to be about 3 times thicker than the steel rim.
[/quote} Sounds reasonable. That's why automotive rims cast out of aluminum are much thicker than comparable size steel rims. Some aluminum rims used for racing are not, but they are not usually cast, but forged or manufactured differently.
Re: beaded edge rims... in alloy?
Posted: Fri May 12, 2023 2:28 pm
by Les Schubert
I just sold a pair of sports car wire wheels with aluminum rims. Certainly the rims were thicker than the other pair with steel rims, but they weren’t rusty!
Re: beaded edge rims... in alloy?
Posted: Sat May 13, 2023 11:40 pm
by Anthony Bennett
I realise that aluminium is softer but there are some with high temper and the surface finish is certainly harder after anodising, in fact it's positively slippery compared to mill finish aluminium.
There are lots of modern 3 piece racing wheels that use aluminium rims, obviously because they're light weight. I've never put a calliper on them to determine material thickness though.
I imagine rolling and welding(?) a T rim could be quite different.