By James Morikawa
29th of December 2006.
Reaming for proper seat-post clearance, usually for 27.2 mm — the most common road seatpost diameter.
Squaring-off the seat-tube . . . with my present grinder set-up. I wrote about "squaring-off the seat-tube" on page 15, but the pictures there are of the process being done on my previous grinder set-up. The above pictured one is the improved version — works better. If I haven't squared-off the seat-tube by now, here's another good time to do so.
Slotting with a cut-off disc. I've install a protective aluminum piece into the seat tube, and mask taped, and marked out where to cut.
Positioning the relief-hole-reenforcement-washer for brazing. Flux has been applied.
The brazing-tool used to hold the washer in position during brazing. Works on gravity. The tool's wonderful idea is not mine. It's a heavier copy I made of the ones Hank Folsum (James Henry Bicycles) gave me many years ago. I think he calls them "braze-on thingamajiggies", or something like that.
Hank Folsum, and George P. Wilson were my most helpful advisers during the my beginning years in framebuilding. I thank them much.
Anyway, I silver-braze that washer to the seat-tube.
Drilling out the "relief-hole"
Using an air-filer with a flat diamond file to finish the slot. I finish the relief hole with a round diamond file.
The finished slot.
I put a slight "V" into the slot. When the seat-post is clamped down, with a seat-clamp, the slot-gap will even out — just a cosmetic thing.
Have a good day. Bye.