A photo essay - the first steps of building Craig's 4" FS 29er.
.083" beef for the pivot (turned down to press-fit, then welded into the upper section of the seat tube), .035" above. Offset to accomodate Craig's super-slack seat tube angle and reasonably short (455mm) chainstays. I'd go shorter, but Craig's going to be sitting pretty far back - so we wanted to keep the rear wheel behind him enough to prevent looping out.
BB/ST/pivot all welded up.
Upper pivot tower and .058" x 1.375" sleeve.
Setting everything up to tack in the upper pivot tower. Gotta double check all those clearances!
Tower welded to sleeve. Here's the complete seat tube assembly:
Still one seat tube step to go - brazing the sleeve to the seat tube to hold everything together (well, ok, the welding of the tower holds everything pretty well, but this is still something I need to do, if for nothing else than to fill the small gaps between the tube and the sleeve)