I'm thinking that I might have a go at drilling out a pair of record large flange hubs. Anyone who has tried drilling a hole in metal knows that you generally need to center punch first, to keep the drill bit or end mill from wandering, especially in those small diameters, and on smooth convex surfaces. I don't think that it is too good a idea to go whacking those delicate aluminum flanges with a hammer and punch. It seems that it is necessary to build a fixture to support the flanges to do the center punching? Even then, caution seems in order. Any advice from someone who has done the operation is much appreciated. Thanks in advance.
Dennis Young Still riding on 19mm tubulars on roads starting to ice up in Hotaka, Japan.