I'm installing a previously used megaexo bb and when I put the crank through it pushed the "dust cover?" off so it wasn't seated. From searching the forums I fixed that problem however after I put the black plastic cover and rubber gasket that surrounded the outside of the bearing back on it would not spin as freely as the DS cup. No matter how many times I tried to put the gasket in and put the plastic cover back it wouldn't spin as freely, it spun easily without the cover so I assumed it must have been that black gasket causing the problem. To test that problem I took the gasket out and replace the dust cover and it spun fine.

My question here is do I need that gasket inside there? And if so how do I get it to not interfere with spinning