PD: Primary Drive Twin clutch drum

[Chris Launders]

Could anyone tell me what the clutch drums are made of please, cast iron, cast steel etc.

 

[Vincent Brake]

I guess its Cast Iron, of a higher strenght.
maybe Nodulair GGG40 or 70

due to Higher RPM i doen't recon its Lamilair GG25

 

[timetraveller]

I know of one that was made Vibrac and it is still on the bike 60 years later.

 

[vibrac]

Vibrac?

 

[fogrider]

Man of steel ? or cast iron !

 

[Vincent Brake]

Cast in Steel??

 

[bmetcalf]

There are cast steel steam valves Valves

 

[RDB58]

Could anyone tell me what the clutch drums are made of please, cast iron, cast steel etc.

I suspect it would a grey iron. If you break one it will tell you what it is by how it breaks. Grey Iron is best for heat dissipation, is easy to machine and is less expensive than other choices. Ductile Iron (SG) was developed in the USA (by a metallurgical accident) toward the end of the WW2 and was not generally used until a decade later. But why would you want to know?

 

[flatyre]

I fitted a one piece friction plate to my Rapide, had to modify the clutch drum by cutting away material at the edge. Easy to cut and file, definitely cast iron.
Dave