Hello, I am a fairly new rider that is just getting into commuting to work. I have a 2006 Bianchi Brava, equipped with all Shimano Sora. There is a triple up front, 52/42/30, and an 8 speed cassette, 12-25. On my ride to work, there are a couple pretty big hills, and with the extra weight I’m working pretty hard. I’d much rather spin up hills than mash, so I’m thinking about changing the Cassette to a SRAM 11-28. My questions are:

1)Will I be able to keep my current long cage 2200 RD, or will I need to move to a Mountain Bike RD like the deore? FYI, the Shimano tech docs say a maximum of 26 teeth, however I’ve read somewhere people having luck exceeding Shimano recommendations.

2)I’ve also read that when you change cassettes you should change chains, however I only have about 600 miles on the bike since new. Can I keep the current chain since it’s probably just getting broken in?

3)For a newer rider, who’s only riding for the enjoyment and weight loss, what does a super expensive Dura Ace/Ultegra chain get me that a Sora chain doesn’t?

Thank you all for the help,

Vince