My road bike, Ironman Master, has a 7-speed cog and rear derailleur. The derailleur is Shimano 600. I'm thinking about upgrading it to more speeds, maybe 8/9/10-speed depending on budget and capability.
I'm not going to change the frame. May I just use the current one with a 8/9/10-speed cog? What should I measure to insure compatibility?
For the parts to be changed, I think that includes cog, rear derailleur and shifter. What else needed? Should I change front derailleur (2 chainring, I want to keep them intact) and shifter?
The cables for front and rear drailleurs look quite old. Does that mean I should change them?
I appreciate any of your suggestion. Thank you very much.