Bottom bracket bearings grinding only when installed into frame I recently purchased a new carbon frame direct from a Chinese manufacturer (link to the particular frame here).  The frame has BB86 bottom bracket. I am using the SRAM Press Fit GXP BB86 Bottom Bracket. Outside of the frame, the bearings seem to run smoothly when I move them around with my finger. However, once I press the cups into the frame, there is a significant grinding/drag present in the bearings. Here is a video that hopefully explains better what's going on.

I contacted the manufacturer of the frame, and they suggested that either the bottom bracket is broken, or has been pressed in "too hard". I'm relatively sure nothing is broken with the bottom bracket itself, since I purchased it brand new. I have also removed and reinstalled the bottom bracket several times with varying levels of force, with similar results. I am using the installation washers included with the Park Tool BBT-90.3 and a long threaded rod with two nuts on either end to install the bottom bracket.  Any idea what's going on?
Bearings are never as buttery once they've been installed, they all feel rougher after they're put under pressure. I put GXP BB90's in my carbon 29er frame and it was the same, though not too bad. It looks like you've installed them properly, it may just be that the frame could be a bit on the tighter side. Riding the bike will loosen things up a bit though, take it for a ride then check the bearings again to see if there's any difference. Unfortunately there's really nothing else you can do about it except hope that it smooths out a little from breaking it in. Those bearings are a closed system, you can't adjust them. The only other solution is to try a different bottom bracket.