See picture below, I am in this situation with a new alluminium frame (don't ask me how I ended up here, it's a heartbreaking story.) It’s a Cinelli Mash Parallax.
The headtube has a dent and I don't know exactly what caused it, but the frame has allegedly never been used. With a bit of a stronger push than usual, my lbs mechanic managed to fit the headset. As for now, the bearings don't seem to be compressed by the dent, but I am still worried. I am going to ride this bike on the track, so I want it to be very reliable.
How safe is it? Do you suggest I try to fix the dent or will I only make it worse?
More photos here: https://i.stack.imgur.com/xhZpg.jpg