Interesting suggestions about just switching the cassette. Thanks.
We have a lot of hills here, and climbing them yesterday my knee started to get sore. I don't want to hurt my knees. There were a few hills where my cadence in my lowest gear was much, much too low. I would love it if the 34 solved my problem.
With the current 28t on the cassette, I have a lower gear than I would have if I switched. I would have the new 34 in its place (for 22 g.i.), but lose the current 28 x 28 (27 g.i.) in favour of a 24 x 28 (29 g.i.)
As I mentioned above, just swapping the cassette only gives me *one* new useable gear, and replaces its sibling with a higher next gear. That's what makes me think it will take a new megarange cassette PLUS a new crankset / chainset.
But, switching the cassette is a logical start. It makes a good first step, from which I can evaluate if further improvements are needed.
I have a loaded tour coming up in Scotland and hear the area is quite hilly. I'd like to get my gear dilemma sorted before this trip so I can test it and make any adjustments in time.