# To S2 or not to S2 ; That is the question.



## Mack the fork (Sep 3, 2021)

As I am nearly ready to assemble my hot rod ‘40 DX Bomber, I’ve now managed to
create another impediment to forward progress.

Although the wheel set is destined to be very cool : prewar Morrow, porkchop, double butted stainless spokes ….

I’m now balking on my choice if rims. 
Currently I have some very nice , painted/striped S2 rims ; But S2’s are not
(to my knowledge) a prewar part.

And there is the rub. 
My build parameters were to adhere to virtually everything being prewar Schwinn .
However, my wallet is of postwar vintage, and this is getting rather expensive.

I DO have a few sets of prewar drop center rims from some non Schwinn ballooners , but unlike the S2’s they’re not stamped “Schwinn”.

Question:  Other than Lobdell, were most drop center rims unmarked and pretty much interchangeable between other bike brands?   What is the history of prewar Schwinn ballooner rims vs the history of the S2 rims ?

Advice needed: 

1)  Should I go with unmarked, and possibly “non Schwinn”, drop center rims for a 
“Prewar look”. ?

OR : 

2)  Should I just use the Painted S2’s 
and “prewar authenticity be damned ?


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## 49autocycledeluxe (Sep 3, 2021)




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## rustjunkie (Sep 3, 2021)

49autocycledeluxe said:


> drop center rims will take a wide range of tires while S-2's take S-2 specific tires. there is a good reason to not use them




s-2's don't require a special tire.
they and drop centers take 559 bead diameter 26" tires

there are many shapes of drop centers, some are specific to brand, schwinn used a particular profile if i'm not mistaken.


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## 49autocycledeluxe (Sep 3, 2021)

rustjunkie said:


> s-2's don't require a special tire.
> they and drop centers take 559 bead diameter 26" tires
> 
> there are many shapes of drop centers, some are specific to brand, schwinn used a particular profile if i'm not mistaken.



so I can hop on down to the local bike shop and buy tires for S-2's? well, you can't to that for S-7's or S-6's unless you want poor quality Kenda's if they carry them. we still have an actual Schwinn shop here in Fremont and he does not carry tires for Schwinn Rims any more. I bought Kenda's there for my middleweight a few years ago. he did not have them for my lightweight. I ended up buying originals.  my S-2 bikes have Typhoon Cords, original and 90's repops. I just put my modern mountain bike tires on some drop centers to get a bike rolling, are you saying those tires will fit on an S-2 as well?  I don't think so.


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## nightrider (Sep 3, 2021)

I have put a huge variety of tires, old and new, many brands, on S-2 rims.
Johnny


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## rustjunkie (Sep 3, 2021)

49autocycledeluxe said:


> I just put my modern mountain bike tires on some drop centers to get a bike rolling, are you saying those tires will fit on an S-2 as well?  I don't think so.



yes, that's what i'm saying. 

they'll fit and work a-ok


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## pedal4416 (Sep 3, 2021)

Any standard 26” 559 tire will fit S-2 rims and drop center rims. That means any new 26" tire will fit. They still make replacement tires for the odd Schwinn S-6 S-7's.

As far as the S-2 VS Drop center rims, that's all your choice. Drop centers look great but so does S-2 and S-2 will be a stronger rim being double walled. Which ever you choose Im sure will look and ride great.


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## Freqman1 (Sep 3, 2021)

I’ll wait for the experts to weigh in but I think on a ‘40 the rims are the same as other Lobdells. Even if they aren’t the same the difference is so subtle few people will even notice. That said I vote drop centers. V/r Shawn


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## sworley (Sep 3, 2021)

Your bike and your preference - whichever look best in your eyes. Personally I’d go S2s cause I think they look classic. Drop centers always looked chintzy to me, likely cause a lot of the later off brands (AMF/Murray?) used a similar looking rim later.


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## Rivnut (Sep 3, 2021)

49autocycledeluxe said:


> so I can hop on down to the local bike shop and buy tires for S-2's? well, you can't to that for S-7's or S-6's unless you want poor quality Kenda's if they carry them. we still have an actual Schwinn shop here in Fremont and he does not carry tires for Schwinn Rims any more. I bought Kenda's there for my middleweight a few years ago. he did not have them for my lightweight. I ended up buying originals.  my S-2 bikes have Typhoon Cords, original and 90's repops. I just put my modern mountain bike tires on some drop centers to get a bike rolling, are you saying those tires will fit on an S-2 as well?  I don't think so.



You can even buy the 26 x 2.125 tires at Wally World or off Amazon.


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## 49autocycledeluxe (Sep 3, 2021)

where did I get this misinformation? is it true of the other sizes? S-7? S-6?


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## WES PINCHOT (Sep 3, 2021)

ALL "USA" MADE "BALLOON" TIRES IN MY LIFE TIME WERE 2.125 INCH.  
THEY FIT ALL BALLOON PREWAR/ POSTWAR DROP CENTER RIMS AND 
ALL POSTWAR RIMS INCLUDING DROP CENTER, LOBDELL DROP CENTER 
OR FLAT TOP RIMS AND SCHWINN S-2 RIMS.

WHEN YOU MOVE ON TO MIDDLE WEIGHT RIMS ONLY 1 3/4  AND "134"
(NOT 1.75) TIRES WILL FIT  SCHWINN S-7 RIMS.  THE 1.75 TIRES WILL FIT
ALL MIDDLE WEIGHT BALLOON NON SCHWINN RIMS.

THERE IS NO QUESTION THAT THE "STRONGEST RIMS" ARE THE SCHWINN
DOUBLE WALL TUBULAR S-2 AND S-7 RIMS.  DON'T WORRY ABOUT WHAT
OTHER PEOPLE THINK ABOUT YOUR RIMS.  USE WHAT YOU LIKE ON YOUR BIKE.

I HAVE NEVER HEARD OF THE DESIGNATED "standard 26” 559 tire".
CAN SOMEONE ENLIGHTEN ME ABOUT THAT "559" TERM?

WES


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## Rivnut (Sep 3, 2021)

559 is metric (mm) of the diameter tire where it seats into the rim.   
559 fits all 26” rims with decimal widths. e.g. 26 x 2.125, 26 x 1.75 etc. (including the Schwinn S2 rims.) 571 is the metric size for the fractional widths e.g. 26 x 1-3/4 tires for the Schwinn S7 rims


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## rustjunkie (Sep 3, 2021)

Sheldon Brown's Bicycle Tire Crib Sheet
					

Useful dimensions and conversions for the cyblist/mechanic



					www.sheldonbrown.com
				









						Tire Sizing Systems
					

Several different systems of size markings for bicycle tires are in existence. The modern ISO system is not as familiar as it should be, this article explains it.



					www.sheldonbrown.com


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## GTs58 (Sep 3, 2021)

49autocycledeluxe said:


> where did I get this misinformation? is it true of the other sizes? S-7? S-6?


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## 49autocycledeluxe (Sep 3, 2021)

WES PINCHOT said:


> WHEN YOU MOVE ON TO MIDDLE WEIGHT RIMS ONLY 1 3/4  AND "134"
> (NOT 1.75) TIRES WILL FIT  SCHWINN S-7 RIMS.  THE 1.75 TIRES WILL FIT
> ALL MIDDLE WEIGHT BALLOON NON SCHWINN RIMS.
> WES




there you go. I thought it was true of fat tires as well.


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## Rivnut (Sep 4, 2021)

You cannot use “middleweight” and “balloon” in the same reference.  Different frame sizes call for different tire size.


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## WES PINCHOT (Sep 4, 2021)

Rivnut said:


> 559 is metric (mm) of the diameter tire where it seats into the rim.
> 559 fits all 26” rims with decimal widths. e.g. 26 x 2.125, 26 x 1.75 etc. (including the Schwinn S2 rims.) 571 is the metric size for the fractional widths e.g. 26 x 1-3/4 tires for the Schwinn S7 rims



AHA!

26 x 1.00 through 5.0559 mmMost Mountain bikes, cruisers, fatbikes etc. Old Schwinn designation was S-226 x 1 3/4 571 mmSchwinn "middleweight" cruisers (S-7)
THANK YOU!
I GUESS I AM NOT TOO OLD TO LEARN SOMETHING NEW TO ME!
THANKS
WES


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## Rivnut (Sep 4, 2021)

Sheldon Brown made up a big chart. I put the info into my own words; Wes appears to have copied and pasted from the same source. Ether way if you separate decimal and fractional tire sizes into two separate groups, Sheldon’s chart is all you need.  There are some exceptions but for older tires. The original Schwinn Tornados and some BF Goodrich tires had 26 x 1.75 tires that fit S7 rims, BUT it was stamped into the sidewalls “For S7 rims.”  Those tires are probably only on display bikes now, not safe to ride.


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## Porkchop & Applesauce (Apr 15, 2022)

I say let’s see the bike and let’s see the choices you have for it.


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## bloo (Apr 15, 2022)

You could use later drop centers. There are several kinds and Schwinn may(?) have only used one profile prewar, but I don't believe they were the only ones who used that profile. Pretty similar looking rims were on a bunch of 50s non-Schwinn middleweights. They are the same size as balloon rims. How accurate do you want to be? Also, there were rims in the 80s by Sun and one other company whose name escapes my right now that look like Lobdell flats but have a welded seam. Huffy also made some rims in the 50s that look like Lobdell flats but are a wee bit wider.

26x2.125 tires on 559mm rims were a Schwinn invention circa 1933. S2 came after the war and the 2 differences are the 1) the stronger tubular construction and 2) they are straight sided, not hooked bead like most of the others. They were still 559mm, and a lot of older balloon tires say "for straight sided or clincher rim" indicating they will work on either an S2 straight sided rim or a more conventional hooked bead rim.

As 26 is the outer diameter, when Schwinn introduced middleweights with narrower tires, they enlarged the rim size to 571mm so the whole wheel and tire assembly was still about 26". That is what we know as the S7 and that is why balloon tires don't fit it. All the competition just made skinnier "26x1.75" tires to fit the same old balloon rims they were using before. They weren't really 26 anymore, but the tires interchange with balloon.

Any 26x2.125 balloon, any 26x1.75 (NOT 26x1-3/4, those are for S-7), and any 26" mountain bike tire will fit.


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## The Spokemaster (Apr 16, 2022)

The key here is 3 simple numbers .... *559*


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## coasterbrakejunkie1969 (Apr 16, 2022)

Thanks, @bloo for the thorough breakdown. You have all the key numbers and info we would need. Great job answering the posters question.


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