# New Guy/First Post, with a Hercules Rim/Tire Size Question.



## Relic Racing (Feb 8, 2022)

Hello everyone & thanks for having me. What a weekend! I came home from an estate sale with two beauties I’ve never seen before. I’m a vintage motorcycle guy, with a few bicycles in my collection, but nothing this cool. 
I apologize if I sound like a moron on this subject, thats why I’m here. School me, masters! 
I purchased a wooden-rimmed Miami & a later Hercules bike. Plans are to ready the Hercules as my swapmeet transportation. I’ve added a Stewart Warner speedo from my “stash”. Just need tubes/tires and it’s ready.
Wheels were already nice & true with nice spoke tension. My question, for now, is will 2.175/2.125 tires fit the rims? I’m aware of the s2/s7 difference on Schwinn wheels, but don't know if it’s an issue on a Hercules. The Miami, I’m not touching it. Much to learn. Thanks in advance
-Thom
ps: can’t seem to post pictures from this iPad. Full storage, something else to fix. (Today)


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## HEMI426 (Feb 8, 2022)

Welcome, when you get the pics uploaded you'll get all your answers.


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## Lonestar (Feb 8, 2022)

Welcome Thom! We'd love to see your pics, both bicycles & motorcycles 😎
Have fun here, it's a great site & some super people!


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## Threespeedmafia (Feb 8, 2022)

Welcome and congrats.  As previously stated, pics will help get the ball rolling.


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## Lamont (Feb 8, 2022)

As to later Hercules,  the answer is prob no , if you are referring to 26 inch modern or balloon tire standard ( labeled 559 iso ) 


likely you would want 26 x 1 3/8  590 mm iso 


best guide to this complicated tire topic is :

sheldon brown 






						Servicing English Three Speeds
					

Many younger mechanics are unfamiliar with some of the idiosyncrasies of English-made 3-speed bikes of the '50's, '60's and '70's. Nevertheless, there are a great number of them still on the road, because they were built to last, and they still come in for repair. An all-around bike mechanic...



					www.sheldonbrown.com
				




and 





						26 x 1 3/8 inch (590 mm) Bicycle Tires from Harris Cyclery
					

Harris Cyclery carries a wide selection of tires, both common and obscure sizes.



					www.sheldonbrown.com
				




Tires ("Tyres")​


t is also important to remember that although 3-speeds usually take "26 inch" tires and tubes, they are not interchangeable with mountain-bike size 26 inch rubber. The vast majority use the English 26 X 1 3/8 size. This has a different bead-seat diameter (I.S.O.590 mm), and will only take tires marked 26 X 1 3/8. This size is also sometimes designated "E.A.3". Occasionally, you may run into a "high performance" English 3-speed that takes 26 X 1 1/4 (E.A.1, 597 mmbead seat) tires.
Older Schwinn 3-speeds used a 597 mm tire marked "26 X 1 3/8", also referred to as S-6. Schwinn 26 X 1 3/8 (S-6) tires are NOT interchangeable with English 26 X 1 3/8 (E.A.3).
Surprisingly, the Schwinn 26 X 1 3/8 (S-6) has a 597 mm bead-seat diameter, and IS interchangeable with English 26 X 1 1/4 (E.A.1)!
I also have *a more detailed article about 26-inch tire sizes*. There are other 26-inch sizes as well!
"28 X 1 1/2" (635 mm) tires used on some rod-brake 3-speed roadsters are a distinct size of their own, and should not be confused with 700C (622 mm) tires which are sometimes also referred to as 28 inch.




This presumes a later meaning post war to 70's Hercules 26 in wheel.   Pics will tell , and you can get a quick answer from the lightweight cabers just with a pic.



 If , in fact you are going to be buying  british standard 1 3/8 tires ,  bike tires direct has a handy ( shorter guide ) , and   prices/ availability  vary quite a bit  ........  have had good deal price on BlySkycycling,  but its hit or miss, and worth comparison shopping

Good Luck! 


you may want to jump to lightweight forum for the Hercules if appropriate


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## bloo (Feb 8, 2022)

As mentioned, a Hercules is probably a UK bike, or it could be an Indian one made in a typical UK style. It is unlikely to take 26x2.125 tires (tyres?), because that was a US thing originated by Schwinn that snowballed here, but didn't catch on so much elsewhere in the world. It's not impossible there could have been a Hercules US-style ballooner (26x2.125) bike at some point, but it is fairly unlikely.

Pictures would help a lot. @Lamont 's post shows what would be the 2 most likely sizes, 5_90mm/26x1-3/8/E.A.3._ or _635mm/28x1-1/2_. If it has rod brakes, most likely 635. If not, probably 590.

Welcome to the CABE!


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## ditchpig (Feb 8, 2022)

On a different tack...to escape the British skinny tire 590mm trap....that frame would likey accept the later everyday 26in. standard rims that you can put the modern 26in tires on that your looking for.....transforming it into a cool swapmeet rat rod of sorts....and might have to settle for  a peddle back brake....this is provided the fork and chainstays have enough clearance. Must see pics! WELCOME! Come back often!
PS... pics of vintage motorbikes welcome.....


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## Relic Racing (Feb 8, 2022)

I noticed today, that the rear is a Taiwan made 26 x 1 3/8”. Not the original, but probably the correct size. The front is unreadable under the crusty brush-on whitewalls. Thanks for all the replies. I’m working on the photos.


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## Rivnut (Feb 8, 2022)

If you can get those tires cleaned up, look for the ISO number as mentioned above. That’s the wheel diameter in mm.  Tires with the same ISO numbers cast into them will work.


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## J-wagon (Feb 8, 2022)

Relic Racing said:


> I noticed today, that the rear is a Taiwan made 26 x 1 3/8”. Not the original, but probably the correct size



Same size as on my hercules there's no way fit 26er 559 ballooner wheel on it. Just too thick for narrow chain/seat stay frame width


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## Relic Racing (Feb 9, 2022)

Relic Racing said:


> Hello everyone & thanks for having me. What a weekend! I came home from an estate sale with two beauties I’ve never seen before. I’m a vintage motorcycle guy, with a few bicycles in my collection, but nothing this cool.
> I apologize if I sound like a moron on this subject, thats why I’m here. School me, masters!
> I purchased a wooden-rimmed Miami & a later Hercules bike. Plans are to ready the Hercules as my swapmeet transportation. I’ve added a Stewart Warner speedo from my “stash”. Just need tubes/tires and it’s ready.
> Wheels were already nice & true with nice spoke tension. My question, for now, is will 2.175/2.125 tires fit the rims? I’m aware of the s2/s7 difference on Schwinn wheels, but don't know if it’s an issue on a Hercules. The Miami, I’m not touching it. Much to learn. Thanks in advance
> ...


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## Relic Racing (Feb 9, 2022)

I was able to upload photos from my smart(er than me) phone. Sorry for the wait.


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## Relic Racing (Feb 9, 2022)

…& this is the Miami.


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## 3-speeder (Feb 9, 2022)

Welcome to the CABE!  Couple of cool looking bikes.  I love that rear reflector on the Herc. Awesome!  Good tire size info from Lamont earlier.  
Generally there is a decent variety of tires to choose from in the EA3 26 x 1 3/8 size but with all the supply issues your choices may be less.


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## gkeep (Feb 9, 2022)

Congratulations on a couple nice finds! They should clean up beautifully. The Hercules looks pre war with those fenders/mudguards or just after. They were still making the arch bar frame in the 1960s, not sure how early though. You might find some answers at this site. https://herculesmuseum.wordpress.com.


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## Relic Racing (Feb 9, 2022)

Thanks everyone. So it’s all about the ISO number, from here. I measured tires on the bikes I own and the 1.75‘s OD is the largest that’ll fit under the front fender. I just want as much tire under me as possible as it will see time on swapmeet fields and fairgrounds. Going to hang the Miami on my garage wall. I think it’s beautiful. Hanging the previous owner’s newsboy cap, off the bars.


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## ditchpig (Feb 9, 2022)

Can't see the Hercules wheel/tire size in the pics ( great shots and very cool bikes) it's likely 590 - British orphan size 26 x 1 3/8... like I've said before unless you throw a standard set of wheels on it, you're size selection is unfortunately skinny and skinnier. Looks like there's some room between the rear stays for more rubber. Thanks for sharing!


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## bloo (Feb 9, 2022)

Yeah, the _ISO gives you the rim size_, unlike the inch sizes, which have been an unfathomable contradictory mess for decades. Not so much because they were in inches, but because they didn't tell you the rim size. ISO also gives you a second number for the tire width and you may find that useful, although some manufacturers may deliver slightly less width than they advertise. In 590 you may be stuck with the original width more or less, but at least you will know approximately how wide.


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## Rivnut (Feb 9, 2022)

I’m running some ISO 559 tires on my 63 Schwinn Traveler (lightweight.) The tires are 26 x 1.75.  Close but I’ve had no rubbing. I’ll have check on the 2nd number when I can shed some light on the bike.


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## Schwinny (Feb 13, 2022)

Those rims aren't very rusty on the Hercules. They may be stamped what they are. Dunlop rims will have the size of 26x1-3/8" or 1-1/4" And then Either EA1 or EA3 . EA1 is 597 ISO and if the rims are original, may actually be the size considering it looks like a pre-war bike. EA3 is 590 ISO and the front tire looks like some 590's Ive had.

Interesting to note that there was an American Hercules Bike of this era made in Cleveland (considering the Miami)
This one looks to be English though.


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## Relic Racing (Feb 13, 2022)

Schwinny said:


> Those rims aren't very rusty on the Hercules. They may be stamped what they are. Dunlop rims will have the size of 26x1-3/8" or 1-1/4" And then Either EA1 or EA3 . EA1 is 597 ISO and if the rims are original, may actually be the size considering it looks like a pre-war bike. EA3 is 590 ISO and the front tire looks like some 590's Ive had.
> 
> Interesting to note that there was an American Hercules Bike of this era made in Cleveland (considering the Miami)
> This one looks to be English though.



Thank you. Lotta’ grime, but little rust on the rims. I’ll be looking for those marks, today.


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## Relic Racing (Feb 13, 2022)

Relic Racing said:


> Thank you. Lotta’ grime, but little rust on the rims. I’ll be looking for those marks, today.



You were right. Going to bed, smarter than I woke. Thanks, again.


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## Schwinny (Feb 13, 2022)

Actually not.....
Araya is a Japanese company so you can bet they are not original.
The question continues....


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## ditchpig (Feb 13, 2022)

Good news actually, now you can feel free to get some standard dime store 26in. rims and enjoy 100s of tire choices.....tempered only by frame clearance.


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## bloo (Feb 13, 2022)

I think these will be the expected 590mm as seen on English 3 speeds, despite the Japanese rims. Araya is high quality stuff, so no harm no foul there. I don't think you will have any trouble getting tires, but probably won't have a wide selection of widths.


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## Relic Racing (Feb 13, 2022)

My head’s spinning. Thanks guys.


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## Schwinny (Feb 14, 2022)

bloo said:


> I think these will be the expected 590mm as seen on English 3 speeds, despite the Japanese rims. Araya is high quality stuff, so no harm no foul there. I don't think you will have any trouble getting tires, but probably won't have a wide selection of widths.



Ok, I'll take the other side and say these are Japanese S6 knockoffs and bet 597's  

I say that because the 597 has been a strictly 1-3/8" tire for a long time (ISO 597/35-37). The 590 is typically found in 1-1/4" (ISO 590/28-32)
But that is today, these rims are from the 70's.
The drum rolls....


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## coasterbrakejunkie1969 (Feb 14, 2022)

bloo said:


> I think these will be the expected 590mm as seen on English 3 speeds, despite the Japanese rims. Araya is high quality stuff, so no harm no foul there. I don't think you will have any trouble getting tires, but probably won't have a wide selection of widths.





Relic Racing said:


> My head’s spinning. Thanks guys.





Schwinny said:


> Ok, I'll take the other side and say these are Japanese S6 knockoffs and bet 597's



The set of Araya S-7 rims are marked S-7 so maybe these are not S-6 rims. I have a set of S-2 style Araya rims marked just 26x2.125


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## ditchpig (Feb 14, 2022)

Not trying to make your head spin any faster, but there should be more info embossed on the two tires. ?


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## bloo (Feb 14, 2022)

coasterbrakejunkie1969 said:


> The set of Araya S-7 rims are marked S-7 so maybe these are not S-6 rims. I have a set of S-2 style Araya rims marked just 26x2.125




Wait, what?! That is confusing. I dont think anything was stamped S7 here, or did I miss something? 

Assuming this is something even semi-normal and located in the US...

 A 26" (not 27) lightweight tire from the 70s, or the bike boom, or back a few years from that has to be one of the two right? 590 as seen on UK 3 speeds and US department store lightweights or 597 Schwinn?

This is why we should NEVER be using inch sizes anymore. It's a mess. It's not the inches vs Metric, it is all the contradictions and if-and-but-or's in the old system.

Hey @Relic Racing, If this bike has any tires on it, please post pics of the markings, or post the markings. If there are inch markings, post. If there are metric markings, post, if there is S-anything or E.A.-anything post that too. I swear we can make sense of this, and probably quickly.


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## Schwinny (Feb 14, 2022)

bloo said:


> Wait, what?! That is confusing. I dont think anything was stamped S7 here, or did I miss something?
> 
> Assuming this is something even semi-normal and located in the US...
> 
> ...



Its not so confusing for those with a few of the bikes with these rims/tires.
Like they did with most things American in the 60's-70's, the Japanese, this time ARAYA, knocked off the Schwinn Special sizes also. I have seen ARAYA Schwinn sized rims before. I wouldn't be surprised to see an S5/S6 Schwinn sized rim (597).
A person could just measure the rim diameter.....

I would have already posted the Rim OD differences but I've put my 26" tire bikes away in prep for me going traveling in a couple weeks.


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## coasterbrakejunkie1969 (Feb 14, 2022)

Schwinny said:


> Ok, I'll take the other side and say these are Japanese S6 knockoffs and bet 597's





bloo said:


> Wait, what?! That is confusing. I dont think anything was stamped S7 here, or did I miss something?



My response was to this post. I was stating that my Araya knock offs are marked as such, so was pointing out they are most likely not S-6 knock offs seeing that they are not marked so.


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## Relic Racing (Feb 14, 2022)

bloo said:


> Wait, what?! That is confusing. I dont think anything was stamped S7 here, or did I miss something?
> 
> Assuming this is something even semi-normal and located in the US...
> 
> ...



I remember at least one was a 26-1 3/8”. I’ll look for anything else, tomorrow.


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## Relic Racing (Feb 15, 2022)

Nothing besides psi/Taiwan/nylon, as far as tire markings go. I think it’s possible that the previous owner swapped out the wheels along with the bars/Hunt-Wilde grips. I probably overthought this. I ordered a set of 26-1 3/8 tires, as were on the bike. If they fit, great. If not, I’ll know what ISO number, it’s not. Should be here Friday. Fingers crossed.


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## rickpaulos (Feb 16, 2022)

I recently acquired a similar Hercules. Only oem parts are the bb and headset.  The wheels are 24 x 1 3/8 UKAI skinny aluminum rims.  They look quite out of place on it so those were removed.  Based on the head badge, it's mid 1950s to late 1950s.  Smallish frame size, I'd say it was intended for tweens or ~5' adults.   Found no catalogs for it.  Experts say Hercules serial numbers are no help in dating.


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## rickpaulos (Feb 16, 2022)

The bike predates the creation of ERTO and ISO so you probably wont find any ISO numbers on the tires.  

You can measure the rims.  The hub gets in the way so use a level .  Take the tire & tube off. Stand the wheel upright on a smooth surface. Place a level on the top of the rim cross ways with the level making contact on both edges of the rim..  Try to get it level.  Measure from the smooth surface to the bottom of the level. That should get you the outer diameter.  Subtract about 5 or 6 mm (twice) to get to the BSD, bead seat diameter.  That should get you close enough to see what the actual size is.  On rims with a bead seat, you can measure down from the top of the rim to the bead seat and subtract that twice.

There are 2 sizes of 26 x 1 3/8. 
26 x 1 3/8 (S-6) 597mm for Schwinn Lightweights
26t x 1 3/8 (EA3) 590mm for most English 3 speed bikes.

English bikes were sold with other wheel sizes.  24" is uncommon and 28" was used on the Tourist models for police and post men.


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## Relic Racing (Feb 18, 2022)

Thanks guys. We’re rollin’!
26-1 3/8, 590 ISO tires fit the 26-1 3/8 marked Araya rims.
The Shcwalbe tires, I went with, are plenty of tire. As beefy as some 1.75’s I’ve seen.
The bike is surprisingly smooth & quiet riding. 
Thanks again. -Thom & Jenny the moto pup.


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## Schwinny (Feb 18, 2022)

And a pretty good tire too.
👍


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## rickpaulos (Feb 19, 2022)

A permanent black ink marker can take are of that modern tire lettering.


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