After watching the RJbikes YT about replacing sealed bearings on older bottom brackets, I bought this worn out on eBay and thought I'd give it a try since I wanted to swap my Veloce group set to a different frame. I had read that the bottom brackets are not user serviceable, and now I understand why.
What I can't figure out is how they even manufactured this! There are 7 bearings on each side and they were held equally spaced apart by the plastic race and covered by a dust cap. I'm guessing that the inner sleeve with the bearing race was pressed in to the outer sleeve, does anyone know if that's true, and if not, how they achieved the magic of putting this together?
by circles08
4 Comments
It’s simply a pair of standard ball bearings that are pressed into the housing and onto the axle. If you want to know how the bearings are made you can look up videos of how ball bearings are made.
You are probably correct on the pressing of the inner race inside the outer sleeve. You would likely need a press and cut the correct size to press this out maybe even heat.
put all the balls to one side and the spindle should shift enough to remove the balls
These type were cartridge, ‘sealed’ BBs. They work fine until they don’t. The aluminum housing is pressed together around the bearings over the spindle, and the outer cups align the whole thing to the frame. Every bike in my bike shop mechanic days of the 90s-early 00s had them of varying quality.
Cartridge BBs aren’t serviceable, just put a new one in. Other usually higher end styles back then would have separate sealed bearings to seat into the frame cups with maybe a plastic or aluminum tube to go between the cups and close off the BB from the seatpost/frame.