I currently have a 1x10 setup with a 42T ring up front and a SRAM 11-28 in the rear. The terrain here on Whidbey Island, WA is far hillier than I had judged from driving around and my first ride here yesterday was a real bear! I'm out of shape, yes, and getting in shape is going to help a ton but I'm beginning to think that even if I were in much better shape the terrain here may require a different 1x10 setup or possibly changing to a 2x10 setup. I don't care so much about hauling serious buns down hills (the current setup seemed plenty fast enough for me and I never was spinning at a huge RPM down the steepest of hills) and I would sacrifice on that end if it meant I could climb a bit easier.
So, if getting in much better shape doesn't cure all my problems (it most likely will, in time) I was wondering about the possibility of swapping out the front ring or the rear cassette to adjust the gearing to be a more hill-friendly setup. As I have never attempted this, what would need to be replaced? Would the chain need to be replaced if I dropped the front down to, say, a 39T chainring? Would the chain need to be replaced if I swapped for an 11-32 cassette and kept the 42T front ring? Would the cranks or bottom bracket need to be replaced? I'd likely take the bike to my LBS to have the work done if it were pretty involved but if putting on a 39T ring simply involves taking the 42T off and then putting the 39T on and requires no adjustment to the chain or anything else, I can handle that.
Would you recommend swapping the cassette or chainring?
Like I said, totally new territory for me so I'm just looking for a little help