Originally Posted by
tFUnK
This is a replacement (conversion?) part that substitutes for BB86, BB90, BB92. Apart from the threaded sleeve not fitting my shell, it looks like it would work to convert my press fit bearings to thread in bearings.
I am wondering if it's as simple as needing to remove some additional parts from inside the shell; when I took it apart it did not look obvious that there was anything else that's removable. The bearings press against the race that's part of the frame itself, but the are are some additional "steps" further inside the shell that step down to 30mm, but I can't tell if they're bonded in or if they're removable. I've watched several videos on YT for a similar upgrade process (press fit BB90 to a threaded Token Ninja) and from what I've seen, all they had to do was pop out the bearings and sleeve and there was nothing else to remove. But the Token part does seem to have a smaller OD threaded sleeve.
Thought I'd check here before I start hammering away at something that may or may not be a removable part.
As I recall, BB90 Treks are just a shell that accepts bearings, and that shell pinches in to stop the bearing from going too far into the frame. Kind of like the removable clips do for BB30. Neither is like PF30 where there is a lip on the bearing assembly that catches on the outside of the frame.
So I would say that the 30mm part is built into the frame to stop the bearing. If not, the maker of the aftermarket BB90 assembly ought to have instructions that reflect how to remove the inner section.