Originally Posted by james_swift
The bottom bracket appears to be seized in the bottom bracket shell. Liberal soakings in WD-40 and persistent banging on the wrench with a hammer to try to crack the lockring free have been futile.
I had the same problem with my BB on my normal sized fixed conversion. I assume you've tried an extension bar such as a long piece of pipe at the end of your wrench? That always seems to help me with seized/hard to loosen bolts and such.
Good luck.
progre-ss aka James