Hi there,
I got this old hardrock off ebay with the intention of putting various newer parts on it including a new seat post. Trouble is, the original post is well scratched so I can't see the right size and haven't got a fine enough measuring tool to measure in 0.1s of a mm. I did see on some other posts that 26.6mm was a common size around this era? the drivetrain and mech are Altus C20 if that helps...
Any help appreciated...