Yeah I know its the tilt thing I was worried about. I can shim it that would be best I think. But the screws do close around the front mount tight. Is that what you mean?Looks like a good choice. Have fun building it. I like that frame.
http://www.diamondback.com/2012-vital-2
Looking at a picture of the bike, I have a couple of concerns. 1) is there enough room between the tubes to mount the front mount? 2) it appears that the frame is 50 degree "V", and will need at least a front mount shim, or a custom front mount. Ideal "V" is 75 degrees. Just throwing my thoughts out there.