Originally Posted by zacster

I swapped a Zeus crank, but not the BB, out and put in a 10speed Chorus crank on my old steelie. I was really surprised by how much less flex there was afterwards. Even if you don't want to permanently change the crank you should try a more modern one to see if that is the issue you are having, although that isn't always so easy or cheap. I had the crank already sitting on a cracked frame.