Recently, I purchased a Gios Spazio road bike that I intend to outfit for self-sufficient loaded-touring. Specifically, I live in Taiwan and intend to do a long tour zigzagging along all three of the cross-island highways as preparation for a longer continental tour.
The problem is that, even without additional weight, I find myself using the lowest possible gears to propel myself up some mountain roads. Currently, my chainset is a 48-38-28T and my cassette is a 12-25T with Shimano Tiaga front and rear derailleurs (I hope I'm using the correct words, my bike parts vocabulary and knowledge are both in their nascent stages.). Hence, it's become clear to me that I need to lower the gearing on my bike.
What I am worried about are compatibility issues, so here are my questions:
1) I would like to purchase a Shimano XT M770 11-34T cassette for the back, which means I will definitely need a new rear derailleur to accommodate the larger cassette. I intend to buy a Shimano XT rear derailleur for this purpose. Am I overlooking anything in the relationship between the rear and the front parts of the "chain system" (?) or is that all I would need to buy?
2) Hopefully the larger cassette will do the trick, but if not, then I intend to change out the chainset to one with a smaller chainwheel with 22 teeth, something like a Shimano XT. Are there compatibility issues with installing mountain bike oriented chainsets onto road bikes? I anticipated having to buy a new front derailleur, but the guy at the shop (in Chinese) tried to explain that the chainset and derailleur would be incompatible with my roadbike shifters. He said I would need to change out the shifters and probably the handlebars, because roadbike shifters need less extension to initiate a shift than mountain bike shifters. (At least that's what I think he said...)
Thanks for any help. We've got until Chinese New Year to get this settled.