Does my crank care whether I'm using 7 sp or 9 sp?
I know, there are millions of variations of the which components care what speed your set up is. I still don't get this one, though. Here's the deal--I bought a used bike, it's running 7sp casette with a triple. It's just about time to get a new wheelset, and I'm thinking it makes sense to build on new 9 sp hubs in case I want to upgrade the whole drivetrain. I know I can use a spacer to run my 7 sp cassette on my hub until I upgrade.
Here's my question--when I upgrade to 9 sp, I know I need to change casette, chain and RD. Do I need to chain my crank or chainrings?
Also, I'm using barcons. I'm not sure what speed they are. How can I tell what speed they are. They're Shimano "light duty" bar ends.
Thank in advance. I know these "what speed" questions get tedious.