my gravel bike in stock form came with a Shimano 105 compact crank. I built mine from a frame, and I had a SRAM double MTB crankset, 28/42. You need 5mm of spacers to get from 68mm to 73mm, which is what most MTB bb are. I had a little bit of trouble getting the front derailleur to go out far enough because I had to put all 5mm on the drive side. I ended up with a Shimano CX70 FD, which shifts fine. It's possible I could have gotten the other FD to work if I had fiddled with it a bit more.