My MTB commuter's rear shifter, chain, and rear derailleur are all due for replacement. Since this bike spends a lot of time locked up outdoors at a college campus I'd rather not go overboard with the best components. I was considering X7 twist shifters, a SRAM SX5 derailleur, along with a new cassette (7-speed now). I have a few questions:
1 The bike has an older (~2001) LX rear hub (FH-M570). I believe this would be compatible with either 8 or 9 speed cassettes. Is this correct?
2 Should I go with 8 or 9 speeds? It looks like I can get the X7's in either configuration. From what I've read 9 speed systems require fine tuning more frequently for good shifts and the narrower chains may not be as durable. Is this the case?
3 Does it matter if the chain brand matches the cassette brand? Do either SRAM or Shimano cassettes/chains tend to hold up better than the other?
4 Should I worry about the chainrings if I am replacing everything else?
I'd appreciate any feedback. Thanks