A cassette doesn't cost much, so I don't mind getting a new one. Besides, the one I have, although not much used, is already showing signs of "ripping" ("sliding"? "slipping", ie. missing some teeth and moving forward more than the right amount) when riding on the smallest cog. Either I'm riding it too hard or it's just cheap stuff.

I wouldn't mind getting 27 speeds instead of 24, but since the World Sport comes with an 8-speed derailleur, I didn't know it was possible to upgrade it to 9 speeds instead.

BTW, what do you mean with "I just happen to like the SRAM 1:1 cable pull stuff"?

I'll report all that information to the mec. Thank you.