I recently attempted to rebuild a sealed cartridge Shimano LP25 bottom bracket. These are meant to be replaced when worn out, but I thought: if someone on YouTube can do it, I can too. The problem is that the top bearings no longer fit, as the first picture illustrates. I am completely certain that these are the exact bearings I removed from the top fixed flange race when I disassembled the bracket. My question is: what exactly is going wrong?
I was attempting to insert the fixed flange onto the spindle incorrectly, the result of a poor diagram made when disassembling the bracket. If anyone else finds this post and needs help reassembling a similar sealed cartridge bottom bracket, here are step-by-step instructions. I wiped down the components before taking the pictures for clarity.
- Insert seal (notched side down) and pack large bearings onto spindle cone.
- Drop fixed flange onto spindle and pack small bearings.
- Insert cone, lock washer and hex nut onto spindle.
- Reseal fixed flange (notched side up)