I think the time has come to replace my rear cassette, it has begun skipping in a certain gear. I'd also like to give myself a bigger granny gear (something like a 28 or 30 would do). I haven't done much in the way of maintenance/buying new parts before so am after some advice.
Bike - Bianchi ML3 Alloy Reparto Corse. The current cassette is a 9 speed. Rear derailleur Shimano 105 Front derailleur Tiagra. Chainset is 105 (looks like 53/39 which I think I'm happy with). Shifters 105 brake-mounted.
So I guess chain will need changing as well, and possibly chainset (it has done a reasonable number of miles).
My question is - when I'm looking at cassettes I see there are a few 9 speed options, eg HG 50, PG 950/970 SRAM, Ultegra CS6500. I'm happy to pay a bit more for something decent. I guess what I have now is SRAM, but I don't know for sure! I very much doubt it's Ultegra. If I did go for the Ultegra would that mean I have to buy an Ultegra chainset too? And what about the derailleurs & shifters, would they need to be changed to Ultegra as well? I don't know what combinations 'just work'. And what about Dura Ace etc?
I am looking at 9 speed because I seem to remember someone saying to me that 9 speed is the most my frame will accommodate, I don't know whether that is right. I can't find any frame specs that tell me that information which is really annoying (maybe I'm looking in the wrong place).
Thanks for the help, apologies for the noob questions.