Didn't I tell you the exact same thing happened with my orange Norman? I went to a lot of effort to straighten the frame, using some big bar clamps and 4x4 timber. Rode straight as an arrow afterwards. But now, months later, the frame tracks to the side again. Nothing else has changed. It really feels like the steel sprang back to where it had been before I straightened it! Well, mebbe not all the way back to where it had been, but part of the way.