new cassette - do I need a new chain?
I currently run a 50/34 ultegra compact with a 10 speed 12-27 rear cassette.
I am just about to buy new wheels, and want to go for a 10 speed 11-27 dura ace cassette upgrade while I'm at it. There won't be any problems as far as derailer settings or chain length etc because of the slightly smaller small cog will there?
As I am buying the wheels and cassette on line, they will be supplied separately. Is it possible to fit the cassette to the new wheels myself, or will it require special tools and a bike mechanic?
Finally, because I am getting a new cassette, will I need a new chain?
I'd appreciate some help.
Thanks in advance.