Seized Bottom Bracket Bearing Cup Races in Aluminum Frames
03-30-24, 10:16 PM
#26
Senior Member
I've heard of folks doing that, and could understand if tough to find replacement. That was my rationale for staying with cup and cone, as I couldn't readjust the preload on cartridges, but even if I could repack a cartridge (I think much more difficult on most), new grease, but still worn loose. That all went away with external BB bearings and generic Tube Spindle 2 Piece Crank (TS2PC (tm), formerly incorrectly referred to as "Hollowtech II style" crank); Can adjust preload, durable, lighter than air, stronger than steel, cheaper than dirt.
03-30-24, 10:23 PM
#27
Newbie
Thread Starter
I guess I don't understand why a cup with cracks in the races would ever get repacked in the first place. You would have to know how to work on bearings without having any knowledge at all of why you're doing it.
And I disagree that the cups are 'bending down into the aluminum frame'. The cups engage both the threads and the end of the BB shell - which is why they are faced. So the cup in the photos was either visibly falling out of the frame, and causing the crank to clunk around, or the threads came apart when the cup was removed.
And I disagree that the cups are 'bending down into the aluminum frame'. The cups engage both the threads and the end of the BB shell - which is why they are faced. So the cup in the photos was either visibly falling out of the frame, and causing the crank to clunk around, or the threads came apart when the cup was removed.
03-30-24, 10:31 PM
#28
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I largely disagree, when I was more novice 3 years ago this would have been extremely helpful knowledge to go by. I hope others can find this info instead of having to struggle with understanding how a BB could be so seized without being corroded at all, along with how to approach such BBs. Many cheap bicycles get lots of work done on them all the time in thousands of shops worldwide, some go through multiple sealed cartridge BBs before they retire.
Above all, this should be a wake-up call that we should stop repacking this stuff.
Above all, this should be a wake-up call that we should stop repacking this stuff.
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Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
03-30-24, 10:43 PM
#29
Newbie
Thread Starter
No one should repack, restore, reinstall, or do anything with damaged parts other than drop them in the recycling bin. Visible cracks, visible thread damage, or any visible damage should be replaced. You are wasting time and risking further damage to the more expensive part…i.e. the frame.
03-30-24, 10:45 PM
#30
Senior Member
No one should repack, restore, reinstall, or do anything with damaged parts other than drop them in the recycling bin. Visible cracks, visible thread damage, or any visible damage should be replaced. You are wasting time and risking further damage to the more expensive part…i.e. the frame.
03-31-24, 07:45 AM
#31
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I don't even look at them anymore. For the mere pennies each I just put new ones in.
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03-31-24, 11:25 AM
#32
Senior Member
Bingo. Grade 25 bearing balls are cheap if bought in moderate or larger quantity. They are also available in stainless - which as I recall, weren't that much more when I needed another batch.
03-31-24, 11:50 AM
#33
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03-31-24, 11:57 AM
#34
Senior Member
I see it as more "belt and suspenders" protection in case of unexpected water intrusion that isn't noticed for a while. Unfortunately, that only helps keep the bearing balls from corroding and spreading junk into the grease, but at least it's something.
03-31-24, 12:18 PM
#35
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However, stainless galls and carbon steel doesn't, so it would not be my choice given the option.
But it isn't important.
03-31-24, 06:35 PM
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I occasionally saw this sort of damage 30-40 years ago, caused by neglect or incorrect maintenance. A single speed or IGH bike can still work (badly, but pedal and it goes) with quite a lot of bearing play. Some of the slack can be adjusted away but tightening makes the balls ride higher up the axle bearing face, the balls already ground their way through the hardened layer of the bearing cups and start to deform the softer steel, pushing it away and work hardening it until it cracks. At this point the bike no longer works, or the adjusting cup has no more thread to tighten, so it arrives at the shop to have its bbkt bearing "grease and adjust" ...
03-31-24, 10:14 PM
#37
Senior Member
Good point, that's true. When I had to service a friend's bike with obvious corroded bearings, I ordered an assortment of balls for all bike part sizes, it had plenty of all sizes and was something like $5 or $7 I think. Same for an assortment of 5 different lengths of stainless rack bolts (5mm?), like 10 of each length, I think $8. I don't buy enough stuff on amazon to make Prime with free shipping worth it, but a friend has it and I'm often fixing their bikes for free, so Bob's your uncle.
