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Chicago Schwinn(10 posts)

Chicago Schwinnchadiscool
Nov 30, 2003 3:37 PM
I just bought a Chicago Schwinn on e-bay but I don't know much about them. Can anyone tell me what the rear spacing is likely to be, or the bottom bracket shell size. It is a 70's model. Thanks in advanced for any help.

re: Chicago Schwinnctpsw
Dec 2, 2003 6:52 AM
what model Schwinn. I have seen many Schwinn Frames that have Chicago Head Badges but are made across the Ocean.
Determine the age here :

and Of course check with Sheldon :
My bet is that your rear Spacing is 120 and the BB is 68 .
Good Luck
Rear dropouts probably 120 mm ...Humma Hah
Dec 2, 2003 9:14 AM
... would be my guess. That's the spacing on both of my '70's Chicago Schwinns, the cruiser and the Paramount. It didn't seem to make much difference ... coasterbrake or corncob, they were all spaced about 120 mm.

What bike did you get? If it has a big BB that used 1-piece cranks, its an "American BB". This was on cruisers and low-end roadbikes. The Paramount and its derivatives would probably be fitted with an "English" BB, very commonly available today.
Rear dropouts probably 120 mm ...chadiscool
Dec 2, 2003 2:40 PM
I'm not sure what model it is. I went to and found out that it was made in Sept. of 1970 but was unable to get any info on it otherwise. I guess I'll know more when I get my hands on it.
General type of frame?Humma Hah
Dec 2, 2003 4:06 PM
From the early 70's, just about all of the Schwinns were made in the same factory in Chicago. The Paramounts were built in a section of the factory called "the cage", very different from the rest of the plant. They were essentially hand-built by a team of four people, and were of lugged steel. They also had a different serial number series. If you don't know what it is, it probably ain't a 'Mount.

Most of the rest of the production would be cruisers like my '71 (frame design almost unchanged since 1938), roadbikes such as the Varsity, Continental, and Collegiate made with similar materials and techniques (typically with one-piece cranks and American BB's, with 2x5 Shimano ders), and derivatives of the Stingray such as the Krates.

All of the bike frames built by the cruiser's method, "electro-forging", are heavy and the ders and brakes were trashy, but the bikes were very solid and well-built, and typically with a really wonderful ride and great handling. The Paramount was a marked contrast, a world-class line of road and track bikes, usually with Campy running gear.

Adapters are available to convert an American BB so that it will accept an English-thread European BB, and thus a more modern crankset. In fact, I have one on order for my cruiser. Its a pair of disks that slip into the old BB, and attach together with three bolts, so no frame mods are needed.

So it sounds, to me (a diehard Chicago Schwinn fan) like you've got a bike on the way that many of us will remember fondly, and which, while not exactly a threat on the race course, ought to be a great recreational ride, durable, and a piece of history from the cycling boom of the 70's. And it is old enough that it should be increasing a little in value. The collectors are more intensely after cruisers from the 50's, but there are folks interested in nice examples of any of the Chicago-built machines, and I'd expect that interest to grow with time.
General type of frame?chadiscool
Dec 3, 2003 5:05 PM
Awesome! Thanks for all the info. I'm looking foward to getting it built up. I'm planning on using it for a quick ride after work, probably no more than 15 miles. Just something for fun. I really dig older bikes for some reason. My regular road bike is a Centurion Elite RS Pro and I love it, friction shifting and all! I'll post pics as the build progresses...
General type of frame?chadiscool
Dec 3, 2003 7:39 PM
Here is the picture from ebay
OK, road frame, American BB, electro-forged headtube ...Humma Hah
Dec 4, 2003 2:47 PM
... notice the sleek radiused joints between the head tube and the top- and down-tubes? That's "electro-forging" (I don't recall any fillet-brazed Schwinns at that time period). The head-tube was upset-welded from two half shells, with those radiuses part of the head tube. The top-and down-tubes were then upset-welded to the head tube, and the resulting flash painstakingly ground off by hand. Its a unique Chicago Schwinn feature, and one of the prettiest things about the frame. VEEEERY strong and durable.

That is going to build up into a fairly heavy bike (electro-forging only worked with fairly thick steel tubing), but that sort of thing doesn't bug me. I would not hesitate to ride the result in a century. Maybe not in the Death Ride, tho'.
Here's the gizmo to convert the BB ...Humma Hah
Dec 4, 2003 2:59 PM

If you intend to make that bike a fixie, you could install a BMX cup and cone set and a BMX or cruiser one-piece crank and chainwheel. Probably steel. You'll probably wind up getting annoyed with the tendency of the chainwheel to work itself off-center, making chain tension hard to set. I lived with this setup for 40 years.

If you intend to put a front der on it, it is possible to scrounge old one-piece cranks with spiders, but I haven't seen one in a bike store in a couple of decades.

I put a Campagnolo Pista track crank on my Paramount fixie, and the thing is so absolutely sweet, I'm going to install one of the converters above on the cruiser, so it can run Campy, too. With the adapter above, you'll be able to use cranks roadies are used to.
Here's the gizmo to convert the BB ...chadiscool
Dec 4, 2003 7:08 PM
Hey thanks a lot for all of your help. I'm not worried if it's heavy, I figure it will just mak me that much stronger. Thanks again...