the taper is done with a 4 mm end mill
its done by using a sub program called a merge
you define top and bottom shapes then the distance for
the merge to take place over , in this case 2 squares top one larger
than the bottom one over a height of 17 odd mm
the mill then cuts in .2 steps (or whatever its set for )
Love it Mikee. This is where I keep saying the whole Retro thing will head to. Just like Hot rodding people will get tired of gathering items to assemble period correct builds (Amyebrook's c26 probably being the ultimate example). Some more advanced "concept" or "theme" builds will start to appear using machined parts that are in the style of the overall build.
How about a Pace 100 with square stem/front forks/ cranks.....?