# Question on Schwinn bottom bracket cups



## Bobrowe (Sep 18, 2021)

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:


			https://www.amazon.com/DONSP1986-Cylinder-Gasket-Motorized-Bicycle/dp/B07PLX5QX6/ref=asc_df_B07PLX5QX6/?tag=hyprod-20&linkCode=df0&hvadid=459584715020&hvpos=&hvnetw=g&hvrand=6390319036675665140&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9061286&hvtargid=pla-942857351226&psc=1


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## 49autocycledeluxe (Sep 18, 2021)

that is not what you want. get original Schwinn parts from Ebay or here on the Cabe. Schwinn used the same size for bikes with one piece cranks for years.

https://www.ebay.com/itm/265317503028?campid=5335809022


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## Bobrowe (Sep 18, 2021)

Okay!  I'll try here first.  But those would fit, correct?


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## Junkman Bob (Sep 18, 2021)

There junk … Take advice and get them here on the Cabe … You can get the proper chainring here on the cabe as well … Welcome


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## 49autocycledeluxe (Sep 18, 2021)

yes those will fit.


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## Archie Sturmer (Sep 18, 2021)

> 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


Bobrowe said:


> 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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## Robert Troub (Sep 18, 2021)

Ok so that's NOT a Schwinn sprocket......so maybe not Schwinn cups?


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## Bobrowe (Sep 18, 2021)

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.


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## Oldbikeguy1960 (Jan 17, 2022)

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.


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## Bobrowe (Jan 17, 2022)

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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## Oldbikeguy1960 (Jan 17, 2022)

Great Man! Sometimes aftermarket fits if you get it for Schwinn, threads are different than almost anyone else.
Nice thing about Schwinn is those parts fit like forever until production went overseas. Even then Tony Lo from Giant Bicycles in Taiwan was building some of Schwinns bikes and I think he may have bought some of the tooling. 
Still on an old classic like that it was good to change it for original Schwinn parts.
That may be what happened, the whole assembly was taken out of a Murray or whatever and the cups may not have fit tight enough for a Schwinn. 
Later AMF/Western Flyer uses that sprocket as well but they built bikes for each other and the parts were from 3rd party manufacturers most of the time.
Glad you got it worked out. I like to see any old bike brought back to life.
Thanks for the reply, Rob


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## Rivnut (Jan 17, 2022)

@Bobrowe It appears that you have the situation resolved.  If not, I have a pair of cups and bearings, you ill need to clean them up, that I'll pay it forward for the cost of postage.  For the cost of freight, I got a bunch of bike parts from a fellow Buick Riviera collector when he cleaned out his late father's garage.


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## Oldbikeguy1960 (Jan 17, 2022)

You cannot buy bearings that good anywhere today.
I am checking, but I may have a Schwinn that could use those bearings if the offer still stands.


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## Bobrowe (Jan 17, 2022)

I’m all set.  Thanks


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## Oldbikeguy1960 (Jan 17, 2022)

I would be able to use those on my 1962 Typhoon. I checked cup size is 2-1/16 as expected.
What would it take to ship them to 
Heyworth Illinois 61745?


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## Oldbikeguy1960 (Jan 17, 2022)

As long as they have tracking you can send them however you think best.


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## Rivnut (Jan 17, 2022)

Oldbikeguy1960 said:


> As long as they have tracking you can send them however you think best.



Sent you a PM


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## AndyA (Jan 24, 2022)

Bobrowe said:


> 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.



Uncle Bob:
Come on, put on a hat and gloves, get out on the road, and let us know how it worked out! We're dying to know! And how about a photo of that new chain ring? Have fun!


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