# Rim and tire sizing.



## rustyspoke66 (Jan 4, 2012)

This information is intended for upgrading tires to make that old 28" tire bike ride nice and be reliable.

Some guys may already know this information but there have been alot of questions about using 27x1-3/8"vs. 700c tires vs. 28x1-1/2" tires.
This information will only pertain to our old 28" wheel bikes and only to using clincher tires not single tube tires that glue on. 

The first most important measurement you will need is the "ISO" which stands for the "International Organization for Standardization". This measurement is used worldwide and knowing this measurement will allow you to find the tires you need that is if they exist.

To find your ISO measurement simply wrap a string around the inside of your rim where the tire would seat, mark the string then measure it. You should come up with a measurement  close to one of the following.

Rim Circumference  in inches.--------------------------------------------- ISO ---------------------------------------------------Trade size tire    

76.97”--------------------------------------------------------------------622----------------------------------------------------700c-----------------easiest to find

77.87”--------------------------------------------------------------------630----------------------------------------------------27”

78.5”---------------------------------------------------------------------635----------------------------------------------------28X1-1/2”            

79.37”--------------------------------------------------------------------642----------------------------------------------------28x1-3/8” -----------very hard to find.        

For the 700c tires the 38mm wide tire is as close to 1-1/2” as it gets some guys will go wider and some will go narrower. 

The 27” tires have been made in several width’s with the most common being 27x1-1/4”. If you’re going to use these tires the largest I could find was 27x1-3/8 but if you can find a 27x1-1/2 please let everyone know where to find them.

The 28X1-1/2” tires can be ordered from your local bike shop or purchased on line. 

The 28x1-3/8” tires are very hard to find but I have found them online in Australia.    http://www.moruyabicycles.com.au/contents/en-uk/d973_28-inch-tyre.html 

A great link for getting a better grasp on the whole tire size thing is.      http://sheldonbrown.com/tire-sizing.html

Any feedback is appreciated and I hope this helps more than not.


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## Iverider (Jan 4, 2012)

Good information!

I think Sheldon Brown should be required reading for everyone getting into cycling or collecting. Talk about a wealth of knowledge. Would have enjoyed meeting the guy.


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## s1b (Jan 5, 2012)

Thanks for posting this!


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## Luckykat32 (Jan 5, 2012)

Great info....thanks for adding it.

Were there more than one size of Steel Clinchers?  I've been told that they were made for a 28 x 1.5"  tires, but I've talked to 2 people who couldnt get 700c tire on their steel Clinchers.



Also, can anybody recommend a site that sells a vintage looking white walls (or gum walls) that will fit on on a 700c rim (hopefully in the US)?


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## rustyspoke66 (Jan 5, 2012)

I believe they did make multiple sizes of steel clinchers. I had a set of G&J clinchers that took a 27" tire and when installed the diameter was very close to 28". We also had a member that had the same G&J rims but with a larger ISO and he could not get anything to fit. I don't now if he tried the 642 ISO or not but nothing smaller fit his rim. I actually have a 642 ISO wood clincher that I need tires for and I found some in Australia but haven't ordered any yet.


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## sam (Jan 5, 2012)

steel clinchers in 700(28s) are quite common as they were the standard rim used on Canadian roadsters.
26x1&1/2" were used on a lot of Girls roadsters.


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## rustyspoke66 (Jan 5, 2012)

Right so the 700-28's would be 622 ISO and I think some tire companies like Continental and Schwalbe still make a tire called 28X1-1/2" that is a 622 ISO tire. Of course I think the standard rims are more a flat profile but I'm not sure as they are not common in the states.


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## fattommy (Jan 5, 2012)

*700c and 29er tires*

Just wanted to add my two bits.  There are tires out now called 29er tires for big mountain bikes, etc.  I believe they are actually 700c with wide agressive treads.  Some might try using these big jobs however they could present problems going through the chainstays.
Tommy


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## bricycle (Jan 5, 2012)

Wow, thanks for doing this! Great info! bri.


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## Luckykat32 (Jan 7, 2012)

*Steel Clinchers & which tires?*

I have, what I believe to be a matching set of Steel Clinchers...one is spoked & the other is not.  The Spoked Clincher measures just over 79 1/4" & the unspoked clincher measures 77 1/8"...those are very different...

do you think adding spokes to the 2nd rim will make it that much larger?  

And, is that going to be the larger Australian tire with the 642 ISO that fits these rims?


I found a couple of tires I want to use on my motorbike & I was told that they are 28 x 1 3/4...is that too wide for a
1 3/8ths tire or will it still fit?  Here's the tires:











I also just purchased a set of the VELOCITY P35s in Teak & in Silver & if a 28" tire will fit on them, can I run a tire that's wider than 1 1/2?   (On the Velocity website it states the P35s as being a 29" tire)


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## rustyspoke66 (Jan 7, 2012)

I would say the 79-1/4" rim is going to be the 642 ISO and the 77-1/8 would be 622 ISO or 700c. One thing I remember about working in the bike shops and changing many tires is that even if they where for instance a 700c they would fit different from brand to brand. Some fitting tighter and some going on easier. I believe the same would apply to rims from different manufacturers. Also the above chart is more or less to help out with what ever we can find in a newer tire that will give some reliability. The ISO has not been used for ever so older tires will be tough to figure out unless you have some rims to try them on.


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## Luckykat32 (Jan 13, 2012)

So you can put a wider or narrower tire on a 700 x 35 rim?  (For example, would a 700 x 32c fit on there?)


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## rustyspoke66 (Jan 13, 2012)

Yes you can but it is not recommended to use a tire narrower than the rim.


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## rustyspoke66 (Apr 17, 2012)

Bump. Lots of rim and tire talk so I thought I would bump this.


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## Balloontyre (Aug 1, 2012)

*Good Stuff*

Just found this thread, excellent info, thanks rustyspoke66


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