Just finished rebuild of 1977 f2. Front end is harsh and forks only move under braking. Even large bumps do not compress the forks. They seem to bind. The forks are new and I am using 10 - 30w Halfords fork oil. When eying them up the forks appeared to be 6mm unparallel from top to bottom. I have changed the bottom yoke which improved it slightly. Any Ideas??