NJRoadBike

I have a vintage 1970's bike with new wheels that are 27 x 1-1-1/4". And I see tire selection for these bikes is 27 x 1-1/8" , 27 x 1-1/4" + 27 x 1-3/8". Will either of these 3 tire sizes be ok on this size wheel or does wheel width need to match tire width exactly?

base2 

Yes.
The number you are looking for is ETRTO size 630x(some number) or (some number)x630, 630 being the diameter of the bead seat in millimeters & the other number being the nominal width on a typical rim.

27 inch is an imperial size tire. Current tire's tend to be sized in reference to metric standard. ETRTO is the industry organization that unified all the various globally found number systems to bead seat & width.

In short any of the 3 sizes you list will fit.

cyccommute 

As long as they are all have an ETRTO size of 630mm, they will all fit. You are looking at only 1/8” between the sizes and 1/4” over all. Not much in the grand scheme of things.

NJRoadBike

Thanks!

Gresp15C

Vittoria Zaffiro 27x1-1/4 appear to be in stock at Bike Tires Direct. All other things being equal, I'd go with the wider tire, for comfort.

Admittedly, I hoarded a pair of them when the pandemic started but the bike parts shortage hadn't yet materialized. Just to keep my old bike going for a few more years

MikeWMass

Somewhat off topic, if the ERTRO number is the diameter, why is a 630 bigger than a 700 which is bigger than a 650?

Gresp15C

I don't know the history of the size designations, but have learned the lesson that the ETRTO is the only thing that's sensibly related to a physical dimension of the wheel.

dedhed

Because a 700 is 622. 700, 650 and some are not ETRTO numbers

​​​​​​https://www.sheldonbrown.com/tire-sizing.html

zandoval 

So... Considering the size now what type of terrain will ya be ridding. For me and my torn up asphalt roads its these two. The Continental Ride Tour is proven. It is absolutely my favorite tire. For gravel ridding I use the Kenda.







I also use Generic Butyl tubes but when the TPU tubes come down in price I am certainly going ta give um a try...

Vintage Schwinn

Hello MIKE w MASS;
Be careful what you call a 650 TIRE designation BECAUSE:
.............................................................................Did You know that the 650 tire = the SCHWINN ONLY 597mm 26 x 1 3/8 tire and ancient EA1 spec. (597mm)
so remember that:
650 = SCHWINN ONLY 597mm, and ancient EA1 specification tire of 597mm
650a = THE COMMON "Everybody Else In the World Except Schwinn" the Everybody Else's 26 x 1 3/8 590mm (37-590)
650b = 584mm
650c = 571mm
.......................so be careful what you call a 650 TIRE even though the old three speed and 1960's and 1970's dept store 10 speed's (650 a 26 x 1 3/8 37-590) has not been typically seen on NEW bicycles sold in the USA since probably about 1984 - 1985.
The 650a 26 x 1 3/8 37-590 tire is still produced in large numbers by about a dozen tire manufacturers, as millions of tourist 3 speeds are still enjoyed in JAPAN as well as Europe and other continents, as well as folks here in the USA that have forty to sixty five year old classic Non-Schwinn 3 speeds,, classic Non-Schwinn 5 speeds, and classic Non-Schwinn 10 speed bicycles in that 590mm 26 x 1 3/8 37-590 "COMMON-everybody else" 590mm non-schwinn wheel size which also is known as 650a.


What you likely commonly refer to as being "the 650" is actually probably the 584mm size which is 650b.


...........................................

27 INCH wheels = 630mm
700C = 622 mm


Traditionally back in the seventies BEFORE TIRE MAKERS BEGAN TO REALLY CHEAT THE BICYCLE TIRE BUYER in actual/nominal tire tread widths,
The typical 27 x 1 1/4 tire for a ten speed was typically a "TRUE" or "NEAR TRUE within + or - 1mm TREAD WIDTH of (32-630)
(32-630) 32mm being the TREAD WIDTH ON THE WHEEL
....................However today's tire manufacturers sometimes "CHEAT" , while a few are TRUE to size......just DEPENDS on the tire model from the particular tire mfr.
What I am describing as "CHEATING" is heck there are some tires today in which a 32-630 (27 x 1 1/4 tire) is actually only approximately really 28.4mm tread width instead of being TRUE 32mm. *****You did not have this wide of a discrepancy back in the 1970's.******* What can I say that hasn't already been said millions of times over the past 35 years..............................you've just gotta investigate the brands and their tire offerings in the 27" (630mm) size on an individual case by case basis.

27 x 1 3/8 tire (37-630)
27 x 1 1/4 tire (32-630)

The inexpensive Kenda K-40 gumwall wire bead tire of 27 x 1 3/8 (37-630) is available everywhere on amazon and out on the worldwide web.
https://www.amazon.com/Kenda-Street-.../dp/B07BVJPVQ6

You might need that 37-630 wire bead K-40 Kenda just to get tires on your ancient Seventies era bike-boom 10 speed to have current rubber which is near to what the original tread width was of that 1973 era, 50 year old 27 x 1 1/4 tire back when you were listening to 8 track tapes, and wearing bell-bottoms and smoking who knows what....


see Sheldon Brown for further detailed explanation on......
https://www.sheldonbrown.com/650b.html
https://www.sheldonbrown.com/26.html

Trakhak

One important consideration for most bikes with 27 x 1 1/4" rims: hook-bead versus straight-sided (or "hookless") rims.

If your rims have inner ridges (labeled "Hook" in the illustration), although they might give a more comfortable ride at lower pressures, you can safely run the tires at or close to the maximum pressure indicated on the tire.

If you rims are hookless, the safe maximum pressure is probably no more than 75 psi. A pressure range of 60 to 75 psi is usually best for both reasonable comfort and efficiency, anyway.

drlogik 

I'm not an expert but 1 1/8" will fit a 1 1/4" wheel with no problems or issues. We did it all the time back in the 1970's and early 80's. They were consider inter-changeable depending on if you wanted a fatter or skinnier tire. Matter of fact, it was considered "cool" to have the skinniest tires. Would I put any other tire on my rim that are not designated for 27 x 1/14 or 27 x 1/18? No, not unless I could be convinced that a new tire is specifically designed for that rim.

Can you fit other tires to a 27 x 1 1/4" rim? Sure, but it doesn't mean that you should. I have an older Raleigh Wyoming that has 27 x 1 1/4" rims and I searched to find a decent pair of 27 x 1 1/8" tires to fit it. I was not going to take any chances.

mihlbach

I've tried a few 27" tires in the recent past. I am most happy with these....https://www.swifttire.com/product/sa...8-folding-tan/

The nominal size is 27 x 1 3/8, but they are really closer to 27 x 1 1/4.

beng1

I would like to know what the fastest available 27" tire is so I can get a pair on my Huffy to run in the TT this summer. I am hoping that with a set of good tires and one other trick I have up my sleeve, maybe I can run as fast as I did last year. When you are in your 60s running as fast as you did the year before is actually running faster. I heard the Continental gatorskins have low rolling resistance.

base2 

I understand you are probably kidding, unless you really do have one of them fancy funny TT bikes 7-11 & Raúl Alacalá made famous...

So just in case:
Panaracer Pasela is quite possibly one of the last really "good" 27 inch tires readily available on the market.

If anyone reader knows of a lighter, better, more supple 630 tire than Pasela that is available for purchase, I am genuinely interested.

HelpSingularity 

The ISO (International Organization for Standardization) has adopted the ERTRO system. The current bicycle tire sizing nomenclature used in the USA is a complete chaotic mess. The ERTRO/ISO 5775 standards will finally release us from this mess. The following link will answer all your bicycle tire sizing questions.​

https://en.wikipedia.org/wiki/ISO_5775

cyccommute 

Because, like the 27” designation, the 700 and 650 size ranges are related to the outside diameter of the tire not the bead seat. Both the 700 and 650 size were 700mm and 650mm, respectively but they each had a A, B, C, or D designation after that number. A 700A was a narrow tire with a small tire diameter. The 700C was a wide tire that fit on a rim with a 622mm bead diameter and a, approximately, 78mm height. The idea was to keep the same tire diameter and change the width and the diameter of the rim to match that size. All tires sizes for bicycles are measured by the metric. They use a mythical “tire height” to get to the outside diameter. A 27” tire, for example, would need to be 2.2” tall to actually reach 27” on a 630mm (24.8”) rim.

’Tis a silly, cumbersome, and throughly confusing system. There are like 6 different “sizes” for the 26” designation and none of them are interchangable,

Edit: My mistake. A 27” tire would need to be 1.1” tall and a 700c tire would need to be 39 mm

tcs

The Pasela PT is nice.

The Schwalbe Marathon Greenguard has comparable rolling resistance, much thicker thread and higher puncture resistance.

The Continental Ultra Sport III has much lower rolling resistance than either.

See:
https://www.bicyclerollingresistance.com/

YMMV

base2 

tcs
Thanks!

FBOATSB

As one who still uses 27" tires, I like to draw attention to this thread in the C&V forum:
https://www.bikeforums.net/classic-v...ce-thread.html
where all 27" tires and who has them is discussed. I thought it used to be a sticky but not now.

JohnDThompson 

While pretty much any 630mm tire will fit on a 630mm (aka 27 inch) rim, the limiting factor may be frame/fork clearance. Measure how much clearance you have with your current tires to see how much wider you may go.

beng1

I ran my 73' Huffy Scout in a local TT last year and averaged 19.5mph over 12 miles. Since I am in my early 60s and getting older and slower every year, I thought maybe a new set of tires and one other subtle tweak may let me keep my speed. Looks like the Continental Ultrasport III is the tire to beat.

Darth Lefty 

This seems like one of those threads that AI chatbots could replace

alcjphil

This was exactly my thought. Frame clearance is more important than rim width for 27 x any fractional size

Erzulis Boat 

Nope. The image of the Huffy TT bike was not accounted for in the Voight-Kampff test.