On Fri, 16 Jun 2006 16:15:32 GMT, John wrote:

I am going to be painting some steel motorbike bits with smoothrite

Use whatever primer you like, Smoothrite is still rubbish. Its only
virtue is that it least it's not as bad as Hammerite!

They're both too hard, too stiff, too brittle and have poor adhesion.
They crack off anything that sees any sort of flexing or vibration,
including chassis parts.

OTOH, Finnegan's primer isn't bad.