Rear Beam Material

[chase saddler]

I am currently in the process of rebuilding my Midas Bronze. Can anyone advise what it was made from and if it was treated in anyway, i.e galvanised. The rust on it after 30 years is little more than surface rust. I intend to clean this off and re-treat but would be interested to know this information

[Rich]

As far as I'm aware they were mild steel.

[chase saddler]

As far as I'm aware they were mild steel.

That was my thoughts. If that is the case it has withstood the test of time very well, which is why I wondered if it were galvanised.

[ACourtney]

The original rear subframes were mild steel finished with yellow-passivated zinc plating. If kept clean, or covered with waxoyl (or other greasy film like stray engine oil) then the zinc plating will last reasonably well. If not and the frame is allowed to get covered in road grime, especially road salt during winter months, then the zinc plating will erode away.
A hot zinc galvanized coating is typically 20-50 times thicker than a zinc plated coating, but the steel needs to be fairly thick so as not to distort when dipped in the molten zinc.

[ilmung]

Hi
Are the other parts of the rear....... mini or metro based ?
kind regards
Geert

[Stuart]

Hi
Are the other parts of the rear....... mini or metro based ?
kind regards
Geert

Mini.

[Inim666]

That's odd as when I bought some rear wheel cylinders the mini ones didn't fit and had to use mk1 metro items

[Stuart]

That's odd as when I bought some rear wheel cylinders the mini ones didn't fit and had to use mk1 metro items

Metro backplates fit Mini radius arms, so that's a possibility.