I currently have a CAAD9-7 that runs 9-speed Tiagra FD and RD. I bought a Sram Rival chainset for the bike, I was told this combo will work. First off do i need to change the chain that is on the bike if it is in good condition? If I do need to swap chain would I simply buy another 9 speed chain?

I am new and still learning please forgive me.

Thanks,
Jess

You mean Rival crankset & chainrings??

Match the chain to the cogs in back. Chainrings don't, within reason, matter much for the number of speeds you're running.

OK so if my current setup is a 9 spd and i'm only changing the chainset/crank, buy a 9 spd chain.

Affirmative?