When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Schwinn BB bearings 64 to 66
- Thread starter J-wagon
- Start date
#eBayPartner Most Recent BUY IT NOW Items Listed on eBay
Excluding anything modern......
Balloon tire era prewar Schwinn uses the 10 bearing cage everyone else did in the US when we still made a lot of bikes. Postwar Chicago Schwinn uses the ever so slightly smaller 9 bearing cage.
The BB shell size is the same on prewar and postwar Chicago Schwinns and most other American bikes with one piece cranks.
You can exchange 9 bearing for 10 bearing as long as you change everything, such as cups, bearing cages, and cones. The crank and chainwheel can stay.
The caveat is that Chicago Schwinn cranks are 28tpi and other US brands of the period were 24tpi. You can still usually exchange one for the other as long as you also change the crank.
In late model one-piece crank stuff of any brand, the old postwar Schwinn 9 bearing (smaller) cages have become much more common. The new bottom bracket sets and cranks that use them are 24tpi though. That combination probably didn't even exist back in the day. If it did, I never saw it. The new production 9 bearing cages themselves fit postwar Chicago Schwinns just fine, as do the new 12 bearing cages.
Balloon tire era prewar Schwinn uses the 10 bearing cage everyone else did in the US when we still made a lot of bikes. Postwar Chicago Schwinn uses the ever so slightly smaller 9 bearing cage.
The BB shell size is the same on prewar and postwar Chicago Schwinns and most other American bikes with one piece cranks.
You can exchange 9 bearing for 10 bearing as long as you change everything, such as cups, bearing cages, and cones. The crank and chainwheel can stay.
The caveat is that Chicago Schwinn cranks are 28tpi and other US brands of the period were 24tpi. You can still usually exchange one for the other as long as you also change the crank.
In late model one-piece crank stuff of any brand, the old postwar Schwinn 9 bearing (smaller) cages have become much more common. The new bottom bracket sets and cranks that use them are 24tpi though. That combination probably didn't even exist back in the day. If it did, I never saw it. The new production 9 bearing cages themselves fit postwar Chicago Schwinns just fine, as do the new 12 bearing cages.
Last edited:
Thx. So sounds like pre-1933 Ballon era was the larger 10 ball bearing (#66), then after 1933ish switched to smaller diameter 9 ball bearing (#64), then around modern 19xx unknown year, maybe 1960s? switched back to 10 ball.
On my 1948 schwinn dx frame (takes the #64 size bearings and matching cup, crank races etc), fitting non-schwinn BB cups (with matching #66 bearings) is very very tight. So I just figured the BB shell was smaller diameter and made to better fit the smaller diameter cups for #64 bearings.
After researching, various sources talk about the smaller 64 bearings in "older Schwinns and 66 bearings (the more universal size) in "modern" Schwinns. But no one seems to have specific or approximate year of transition. Just curious.
On my 1948 schwinn dx frame (takes the #64 size bearings and matching cup, crank races etc), fitting non-schwinn BB cups (with matching #66 bearings) is very very tight. So I just figured the BB shell was smaller diameter and made to better fit the smaller diameter cups for #64 bearings.
After researching, various sources talk about the smaller 64 bearings in "older Schwinns and 66 bearings (the more universal size) in "modern" Schwinns. But no one seems to have specific or approximate year of transition. Just curious.
More like 10 ball from sometime before 1933(?) through 1941, and 9 ball basically forever after 1945. It certainly didn't change until Chicago Schwinn shut down in the early 80s, and my guess is it didn't change for a long time after that. Considering that 9-ball has become the new standard in Chinese replacement bottom bracket sets, maybe it never changed? Maybe there's some Wal-Mart Schwinns with 10 bearing sets in them? I don't know. I'm sure it didn't change in the 60s.
There was never as far as I know any oversize cups made just because of the bearing cage size. Some manufacturers did have a larger bottom bracket hole for various reasons. Getting oversize cups for a frame like that can be a problem, although I think Wald makes a 10 bearing set with 3 bumps on the cups that is oversize and you can file the bumps off to get standard size.
If you want 10 bearing in that frame for some reason, my guess is any cups out of almost any old American frame will fit. Also, 1941 or earlier Schwinn.
Archie Sturmer
Riding a '38 Autocycle Deluxe
# 66 to # 64.
Some good information in this thread, even for normal non-A&S bikes; and consistent with some of the old catalogs posted.
thecabe.com
What I like about the even-numbered count of ball bearings (10 or 12 each), is that some otherwise similar retaining cages may be measured across the flats.
Some good information in this thread, even for normal non-A&S bikes; and consistent with some of the old catalogs posted.
Paper Archive: Catalogs, Instructions, Schematics. Non-Discussion Thread | General Discussion About Old Bicycles
A couple of bearing charts showing what each maker used. First from Chicago Cycle Supply 1938. Second from 1950 catalog.
thecabe.com
Ok. I see! I had numbers and sizes perhaps flipped around in my head. Confusing. So regardless of bearing 64 or 66, the BB cup outer diameter should be same and I can swap between schwinn and non-schwinn frames pre/postwar era. And the cups should just press in easily by hand and not need a rubber mallet to press in.
Almost all frames yes. You might need to tap with something, but it should go in fairly easy. The cups are meant to be tight and not spin. If it doesn't want to go in, something is wrong. I don't think youll have trouble on a Schwinn frame, but some frames have stuff in the way inside the bottom bracket hole. It pays look and be sure the cups aren't bottoming out on something.
[UPDATE see post #12]. After some internet research, some specific date ranges for Schwinn bottom bracket / crank bearings 66 (10 ball) and 64 (9 ball) are:
Prewar up to 1942/1946ish: #66 / 10 ball
1942/1946ish - 1980: #64 / 9 ball
Post 1980: 10 ball
Date cutoffs fuzzy but I have a better idea now.
Prewar up to 1942/1946ish: #66 / 10 ball
1942/1946ish - 1980: #64 / 9 ball
Post 1980: 10 ball
Date cutoffs fuzzy but I have a better idea now.
Last edited:
