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Question on Schwinn bottom bracket cups

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Bobrowe

Look Ma, No Hands!
I am fixing up what I believe is a 1948 BFG Schwinn. The bottom bracket was caked with grease. I usually take everything apart, clean and put it back together, but when I finally got down to the metal cups, I discovered that one of them is all torn up. When I measured the inside shell of the bottom bracket, I got 2 1/16 inches. The replacement cups I see on line say that the inner diameter should be exactly 2 inches. Will those replacement cups work on my bike? By the way, I punched these old cups out without any issue at all. I've never replaced cups before. Is it as easy as it looks?

Here is the link for the replacement cups:

Chainring.jpg


whole bike.jpg


bottom bracket cups 1.jpg


bottom bracket cups 2.jpg


bottom bracket cups 3.jpg


Serial Number.jpg
 
Schwinn used the same size for years
Was that same size an oversized proprietary 2+1/16” (2.06) ID just like OP measured?
Did A&S not use common 2” interference-fit cups (2.02)?
What was that same size, (inches or mm)?

We understand the other part about Murray chain ring sprocket may fit an A&S bicycle, but might be frowned upon as an aesthetic mismatch:(
When I measured the inside shell of the bottom bracket, I got 2+1/16 inches.
That seems quite large; could it have been a fractional 2+1/32”?
Bottom brackets sometimes wear on the inside, perhaps compare the fit of the existing cups on alternately on each side to see if one side of the bottom bracket is worn more than the other, or if they are the same.
Also, understand that 2” is a nominal size, and that the bottom bracket cups should have an interference-fit, within tolerances.
 
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This bike is going to be a rider, so the Murray chainring is okay. The wheels are also mismatched and kind of a mess. It would take a lot more than it would be worth to get it original.
 
I know this thread is old but if someone refers to this for an answer to their problem, I want it to reflect these thoughts.
I would never put bearing cups in a frame that were too small for the opening.
Your openings are 2-1/16" and the cups popped out easily. If the cups are the right diameter (interference fit, that is what keeps them tight) there should've been a little more resistance to get them out.
Perhaps that is why the one cup is torn up. If they have ever been replaced before and did not fit tight enough, it may have been rotating in its opening and chewed up one side of the cup.
1/16" may not sound like much but it is .0625 in decimal numbers and for anything bearing related that is a lot. Equivalent to boring engine cylinders to .060 (60 thousands of an inch), which is maximum overbore for a lot of engines.
Imagine boring engine cylinders to .060 and putting stock bore pistons in. It wouldn't run properly, and would have a hollow knocking noise from piston slap. Eventually it would crack and break piston skirts, destroying part if not all of the engine.
This same concept applies to any bearings on the bicycle whether they be wheel, headset or bottom bracket the problem is the same.
I hope this puts the problem in perspective if not for the OP, then maybe for anyone who refers to this post for an answer to their own bearing related question.
 
Well, I did get a Schwinn chain ring and bearings and cups. The cups fit fine although I haven't given the bike a proper shake down cruise since I was working on other parts and then it got cold.
 
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