Originally Posted by
bsyptak
Don't think it will work. XTR is meant for a 22-44 crankset. Road is typically 3x-52. I've only read that it won't work correctly. If it worked correctly, Shimano wouldn't have come out with the flat bar road shifters & front derailleur.
However there is this:
Before the flat bar road shifters were marketed, many tandems and some hybrids came from the factory with road bike cranks and front derailleurs paired with mountain bike shifters. It was a common combination. My wife has a hybrid that came from Specialized equipped with a Tiagra front derailleur and LX shifters. My daughter's tandem uses a road style crank, 105 front derailleur and LX shifters. I KNOW that both of them work correctly because I've tuned them both.
For some reason I'm told that the opposite (road brifters and a mountain bike front derailleur) doesn't work. That's, however, a combination that I've never tried so I can't speak of that combination from personal experience.