It has become apparent that disc brakes are here to stay and that if one wants to use a carbon fork then the only real option is to have a tapered steerer and through axle. While frames that are tig welded or fillet brazed can accommodate these upgrades without much difficulty, (particularly if you don’t mind the look of a large diameter head tube) I rather prefer the slimmer look of a tapered head tube and lugs. Unfortunately lugs for a tapered head tube are non existent and to that end I decided I had to make my own. Given the lugs that are available, this does only mean the manufacture of the lower head lug. I decided that the best starting point was a flat sheet cut into the undeveloped shape I wanted to arrive at
. I turned up a dummy head tube out of solid steel and with a bit of heat to help me along I bent the sheet around the dummy. I brazed up the join and then set about making a fixture to hold things together.
Having a tapered head tube meant that I couldn’t take the angle off the outside of the tube. I decided to hold the head tube with the start of the lug on it between cones. I held the 35mm down tube port in a block at the same center height as the cones and set that block at the required angle. This let me file things up. Once that was done it was a matter of fillet brazing the said down tube port to the head tube ring and then dressing the lug to the way I wanted it.
I am pretty happy with the way this has turned out but if you want to see the intended end result you had better plan to be at the Handmade Bicycle Show in Melbourne next April. In the mean time have a great Christmas