Bottom Bracket Threads Worn Away (Not Stripped)
I have an oddball problem with the bb of my '90 Trek 420 frame. I bought the bare frame (it's REALLY bare, not even paint!) at the local co-op and it had a piece of an aluminum bb retainer or cup (couldn't tell which but it did say Shimano 600 on it) on the non-drive side that I had to chisel and saw out of the shell. Those threads are OK in that side but on the drive side the threads on the outer half of the shell (facing the crank) are simply worn away. I inserted a fixed cup in the shell and it just slides in until I get down the the last 1/8 inch from the shoulder of the cup and then it "catches" the good threads an just tightens up like normal.
My question is since the fixed cup is snug and tight like normal I'm still afraid to actually ride the bike like that. There doesn't seem to be enough threads to keep in place under load. I don't know if it will hold or not since I didn't install the crank yet. It might be just fine for all I know.
I was thinking of getting the threadless bb that Velo-Orange sells but that's kind of pricy. Should I go this route or just use a conventional bb?