Hi Guys,

Building a touring type bike - I'd like to use STI shifters but with components offering a lower/wider range of gear inches than a road groupset would offer.

I've been looking at Tiagra 4700 10 speed STI shifters with a Shimano XT M785 10 speed dbl chainset (24.38t) and 10 speed MTB cassette (11-36t).

I've read about the ability to cross over road and MTB components given the correct capacity derailleurs. Are there derailleurs out there that would allow me to combine the above components?

If the above combination is ridiculous could anybody suggest a drive train combination using STI shifters (and preferably a double chainset) that could provide gearing in the region of 18" - 100" (700 x 32 wheels).

This is the first time i will be building a bike from scratch so my expertise / knowledge is limited.

THANKYOU!