Expanding the range of capabilities of a gravel bike I'm a believer in having just one bike that i can use for anything I do, mostly club rides and light touring. I currently have a Giant Defy 1 with 28c tires, but am intrigued by the new gravel grinder bikes such as the GT Grade, which have road bike components but accept broad tires. I'd like to make a few changes to a GT Grade, and would appreciate any guidance on a few questions I have:


I'd like to replace the road bike transmission (Shimano 105) with a mountain bike transmission Shimano XT), both 11 speed.


Is it possible to make the change? Will an XT crankshaft fit on a road bike?
Can i use the 11 speed 105 shifters to shift the XT front and rear derailleurs?

I'd also like to replace the wheels (Stan's No Tubes Grail Disc) with XT wheels, which i expect would be more robust when touring. The XT wheels have an internal width of 24 mm. I believe they will fit the bike, but will they work with 32c tyres (Conti Gatorskins or Schwalbe Marathon Supremes)?
To me, gravel bikes seem mostly like cross bikes with a bit more money they can take from your wallet. 

1) Road and mountain shifters and derailleurs don't play nice with each other at 11 speed, so this question is moot. If you want to check a particular crankset on the bike, look at the width and the type of BB setup. I don't see why you'd want to switch to a mountain drivetrain in the first place. 

2) If a wheel is 700c, you can technically mount any tire on it thats 700c (though you'll have problems if too narrow or too wide). If you look at the width compatibility chart from Sheldon Brown, you'd want a rim with a smaller width. Since you're upgrading, may as well buy the right width. By running this, you increase the risk of pinch flats/rim damage over a more well matched width.