I cut the head tube down on my CycleOps 300. It was pretty straightforward. I thought I posted it somewhere in this forum but I don't remember.
The "before" picture - this was me thinking in picture:
https://1.bp.blogspot.com/-xAs28QeNX...ModsSketch.jpg
Planning. Note the top cast piece held on by a few spot welds (not sure if that's the right term). Also note how tall it is. I'll need to cut it down.
Next was the doing. It's a modular system as I hoped. I didn't think such a frame would be made with hand built loving precision stuff. No, it would be cast and tacked/welded/glued. And it was.
The cut original head tube (in front), the stuff I had to mod in the rear.
The top cast piece in front. It came off the black painted area of the tube in the rear. Once I cut through a few spot welds and pried through some epoxy it popped right off. I had to cut down the cast piece to make it as low in height as possible. Don't lose the black plastic spacer that goes in front of the spring.
Finished and nicely low. Note how the top cast piece is much shorter than original. I cut the head tube down to minimum and trimmed the cast piece so it would stay on. I also had to cut through some stuff at the bottom of the head tube since the "stem" now drops well below the bottom of it. Now for the stem mod.