I went to fit the roll bar and found that it was 6mm too narrow for the airframe. It would bolt in, but loads the airframe and itself. I had a browse on VAF and found that I was not alone. I saw one method of using an engine hoist to stretch it, but decided to use my hydraulic press as per image #1. I measured the ram extension and stretched it in 5mm incriments. Plastic change started at around 55mm ram extension, and 60mm made it perfect. There was a lot of springback! The rest was quite straight forward, however I had to employ a 0.032" shim under the right side, forward of the hoop, along the upper longeron. Sorry for switching between metric and imperial (not sorry :) ).
