Originally Posted by
scarlson
Ha, yep! And I'm still commuting on that bike daily! Used it to help a friend move a 45lb Zeiss microscope in the snowstorm last week, and just braved the Boston traffic on it today to ride to a fish market and then to work to do a couple experiments. I am confident the frame will break again - just not in that spot!
The OP has the compound problem of needing a sleeve up in the head tube, but it could be done in two operations, independent of each other. First the sleeve, then the fillet, I reckon, since the fillet seems easier both to do and to see what you're doing, not being up inside a tube and all. In any case, it will be strong after it's done!
I guess if I'm really dreaming, I've always said if I get a custom bike I'll pay the extra money for bilam head lugs with a stainless steel head tube. But that doesn't sound like a good place to start on my first brazing project.