Primers for prepping parts and 2K Max is for a hard professional coat. Offered here at very low prices.
Do I Need to Prime My Bike?
Is it bare metal? Yes. You will need Spray.bike metal primer or a combination of 3M self-etching primer and then a coat of Hi-Build Primer before painting. In a pinch, Rustoleum Aluminum and Paint Primer will do.
Is there good paint on it but you just want to paint over? No. No primer is needed. You can use a scuff pad, wipe that clean, and then lay down your base coat.