Got that stupid piece of bottom bracket adjustable cup out, just had to slot it a little with a hacksaw blade. It cut like plastic, then just chipped out, so I guess I’m grateful for that. Now to get a bike shop to chase the BB threads. I have sprayed a bunch of WD-40 down into the seat tube, top tube, and down tube in the hopes that it will abate some of the rust that seems to just be everywhere inside that frame. Blech, bad purchase, but whatever, it’s kind of neat looking, plus I am kind of fond of that u-brake.
I’ve heard nothing but bad things about ISIS bottom brackets, but I’m loathe to chain myself to octalink, which has already been usurped like three times by Shimano’s own products. Maybe I’ll just stick with a frickin’ square taper. I could go with an external bearing model, but they’re pretty dear.