Shimano BB bearing replacement tools

[mattthemuppet]

made a set of adapters to press the bearings out of Shimano outboard bottom brackets and press in off the shelf cartridge bearings. A) because I'm cheap and b) because I can

making the doodad to press the bearings in - first trepanned a chunk of alu to make some custom spacers for the bottom bracket


then turned down the stub


then parted off from the chunk


pressing out the old bearings. Used a piece of black iron tube to hold the shell and some random steel as the pusher. One of the shells needed the ID opened up to get to the back of the old bearing


pressing the new bearing in


finished job


collection of parts (inc. new spacers and old plastic ones)


the bearings spin much more freely than the old ones, even when they were new, and I got 10 decent ones (Abec 5 supposedly) off Aliexpress for $16, so I can do the bearings on my other bike and still have 3 sets left over!