Why 27" / 630 mm wheels?
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I found it interesting that, around 1990, Some 700c MTB's were sold and used a 700x45-sized tire on a narrow rim.
I later raced on such a bike that I re-purposed from the world of replica antiques, long story but the tires were available for as long as I still needed them.
Much later, the 700c mtb came back, but as a "29er" with wider tires.
Yet Panaracer (who made my old "Smoke45" tires), in recent years introduced a FireXC45 tire, basically an updated tread on the old Smoke45's.
WTB tried to get everyone thinking in metric widths, both casing width and tread width, but eventually added the old inch sizes back onto the sidewall info.
I later raced on such a bike that I re-purposed from the world of replica antiques, long story but the tires were available for as long as I still needed them.
Much later, the 700c mtb came back, but as a "29er" with wider tires.
Yet Panaracer (who made my old "Smoke45" tires), in recent years introduced a FireXC45 tire, basically an updated tread on the old Smoke45's.
WTB tried to get everyone thinking in metric widths, both casing width and tread width, but eventually added the old inch sizes back onto the sidewall info.
#52
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One of the funnest parts of working at a bike shop is trying to find out which 26" tire a customer wants. 559, 590 or 597 covered most that dropped in when I was doing so.
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Now the imperial system for off road tires on the other hand is beautifully simple. 33x12.5x15 would describe a tire 33" in diameter, 12.5" wide for a 15" rim. That's the standard we ought to adopt. I don't even care if it's in inches or millimeters, what matters is that it's simple and accurate. Anyone can understand outer diameter, width and rim size.
#54
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I finally switched my wife's Shogun 400 from 27" to 700C. That way I can swap in one of my tubs if she gets a flat (or 2 flats, since I built 2 sets of 700C wheels for her). I gave the 27s to an LBS, they had very little use and had never been crashed.
Found 2 pairs of nice, unused, polished Araya 700C red label rims. one pair has eyelets and the other does not.
As for my bike, I built 5 pairs of Mavic Championnat Du Monde Professionel (2), Super Champion Record du Monde (2) and MilRemo Super Club (1) wheels all on Campy Record Low flange hubs. All with New (30+ yrs old, but new) Berg Union chrome double butted spokes with the 4 leaf clover on the end, just like the bike originally came with. All 36H tubs. I should have enough wheels for the next 20 years.
Found 2 pairs of nice, unused, polished Araya 700C red label rims. one pair has eyelets and the other does not.
As for my bike, I built 5 pairs of Mavic Championnat Du Monde Professionel (2), Super Champion Record du Monde (2) and MilRemo Super Club (1) wheels all on Campy Record Low flange hubs. All with New (30+ yrs old, but new) Berg Union chrome double butted spokes with the 4 leaf clover on the end, just like the bike originally came with. All 36H tubs. I should have enough wheels for the next 20 years.
Last edited by cadillacmike68; 07-13-14 at 12:57 AM.
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Agree entirely, but it's actually even worse than you describe. Standard automotive tire sizes start with the tread width in millimeters, then the next number reflects the percentage of the tread width that would account for the sidewall, then there's finally the rim size in inches. So, 205/70/R15 would describe a tire with a 205 mm tread width, 143 mm sidewall and 15" rim and you'd practically need a slide rule to figure out the diameter of the stupid thing.
Now the imperial system for off road tires on the other hand is beautifully simple. 33x12.5x15 would describe a tire 33" in diameter, 12.5" wide for a 15" rim. That's the standard we ought to adopt. I don't even care if it's in inches or millimeters, what matters is that it's simple and accurate. Anyone can understand outer diameter, width and rim size.
Now the imperial system for off road tires on the other hand is beautifully simple. 33x12.5x15 would describe a tire 33" in diameter, 12.5" wide for a 15" rim. That's the standard we ought to adopt. I don't even care if it's in inches or millimeters, what matters is that it's simple and accurate. Anyone can understand outer diameter, width and rim size.
#56
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What's remarkable is that so many 27" tires are still being made for a rim size that was phased out thirty years ago. Samsung no longer makes the battery for my two year old cell phone.
27" was the most popular wheel size in the U.S. when FOUR MILLION bicycles were sold here in just four years. And a lot of these bikes are still on the road today. I was visiting NYC this weekend and saw dozens of thirty and forty year old bikes being used. It says a lot about the fundamental soundness of the "10-Speed" design.
27" was the most popular wheel size in the U.S. when FOUR MILLION bicycles were sold here in just four years. And a lot of these bikes are still on the road today. I was visiting NYC this weekend and saw dozens of thirty and forty year old bikes being used. It says a lot about the fundamental soundness of the "10-Speed" design.
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I think the real ideal is a tire size based on the rim size, with a factor for tire size, for example a tire with 622-17 would fit a 622mm diameter x 17mm wide rim. Then add the outside diameter so, a tire that is 700mm outside diameter, would be 622-25-700 this could be applied to All tires, so a car tire that fits a 17" wheel that is 6" wide that has an outer diameter of 23" would be, 432-15-584 Then add a letter code to define the tire type. A manufacturer would simply need to specify the rim size and the maximum tire that will fit.
There are probably dozens of ways that it could be standardized that would make good sense so long as it were simple, uniform and informative. What's amazing is that hardly any of the common tire sizing standards are any of those things. You'd think that at some point someone would get it right and then everyone else would jump on the band wagon.
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More to the point; why isn't everyone using ETRTO designations? In automobiles, trucks, motor vehicles - just about everywhere else, tires are designated by the bead seat diameter (BSD). It would a great deal less confusing for everyone if bicycling followed the same standard.
(A-nother Mechanical Design and Release Engineer).
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Dont forget 507mm for 24" kid MTB's, 571mm for 650c (26" narrow road tires) both are fairly common. There are also a couple of other 20" wheel sizes that all use different rims. I
nterestingly, the outer diameter of the tire for both 507mm and 571mm are very close. I converted a 24" mtb frame into a road bike for my daughter by switching it to 650c wheels and fork and drilling the frame bridge for a road brake on the rear tire.
nterestingly, the outer diameter of the tire for both 507mm and 571mm are very close. I converted a 24" mtb frame into a road bike for my daughter by switching it to 650c wheels and fork and drilling the frame bridge for a road brake on the rear tire.
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what about the history of width sizes for 27" tires for mid/upper level bikes?
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
.
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
.
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
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What's remarkable is that so many 27" tires are still being made for a rim size that was phased out thirty years ago. Samsung no longer makes the battery for my two year old cell phone.
27" was the most popular wheel size in the U.S. when FOUR MILLION bicycles were sold here in just four years. And a lot of these bikes are still on the road today. I was visiting NYC this weekend and saw dozens of thirty and forty year old bikes being used. It says a lot about the fundamental soundness of the "10-Speed" design.
27" was the most popular wheel size in the U.S. when FOUR MILLION bicycles were sold here in just four years. And a lot of these bikes are still on the road today. I was visiting NYC this weekend and saw dozens of thirty and forty year old bikes being used. It says a lot about the fundamental soundness of the "10-Speed" design.
What do folks consider to be the 'highest-performance' 27-inch tire currently available? The Paselas are decent, the Conti Gatorskins are tough, but neither is really a high-performance tire, these days.
Last edited by 753proguy; 07-13-14 at 10:13 PM.
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what about the history of width sizes for 27" tires for mid/upper level bikes?
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
.
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
.
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
Edit: Measure the inflated width of your Paselas. They are notorious for being narrower than stated, in many cases. You may already be running 23s!
Last edited by 753proguy; 07-13-14 at 10:20 PM.
#63
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There could have been 27" tires 1" or narrower long ago and I just never saw any whenever I was looking to buy tires. As I remember it Specialized came out with 1 1/8" tires rated for 90psi some time around the late 70's or maybe as late as 1980. They seemed a radical innovation at the time compared to the common Michelin or Hutchinson typically rated at 70psi. I bought some as soon as I heard about them, really like them. Maybe a year later they introduced a 1" tire rated at 95psi and then 100psi. I tried the 1" variety too, like them.
I don't recall the exact dates for any of these though. And as I say, narrow high-pressure may have been available before them, but just not commonly available. More often than not high-performance bikes had tubulars anyway.
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There could have been 27" tires 1" or narrower long ago and I just never saw any whenever I was looking to buy tires. As I remember it Specialized came out with 1 1/8" tires rated for 90psi some time around the late 70's or maybe as late as 1980. They seemed a radical innovation at the time compared to the common Michelin or Hutchinson typically rated at 70psi. I bought some as soon as I heard about them, really like them. Maybe a year later they introduced a 1" tire rated at 95psi and then 100psi. I tried the 1" variety too, like them.
I don't recall the exact dates for any of these though. And as I say, narrow high-pressure may have been available before them, but just not commonly available. More often than not high-performance bikes had tubulars anyway.
I don't recall the exact dates for any of these though. And as I say, narrow high-pressure may have been available before them, but just not commonly available. More often than not high-performance bikes had tubulars anyway.
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I keep seeing this statement repeated, but both pairs of Paselas that I have measure exactly what the sidewall says they should. The 27x1 is 1 inch wide and the 27x1 1/8 is 1 1/8 inches. I have tires from other companies that are a full size narrower than advertised, as in a 700x25 that is really 23mm and a 27x1 1/4 that is really 1 1/8".
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what about the history of width sizes for 27" tires for mid/upper level bikes?
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
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In fact, I don't recall ever seeing any reference to hooked rims at all back then. Of course I may have forgotten. I ran them at the rated psi on the straight-sided Fiamme Yellow Label clincher rims, not a superb rim but light. Never had a blow-out until recently when I tried running a 25mm Pasela on them at its rated 115psi. That prompted me to rebuild the wheels with different rims.
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I keep seeing this statement repeated, but both pairs of Paselas that I have measure exactly what the sidewall says they should. The 27x1 is 1 inch wide and the 27x1 1/8 is 1 1/8 inches. I have tires from other companies that are a full size narrower than advertised, as in a 700x25 that is really 23mm and a 27x1 1/4 that is really 1 1/8".
Last edited by 753proguy; 07-14-14 at 08:04 AM. Reason: typo.
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Mine too. All five bikes within a mm or what they claim to be, certainly not a whole size too small.
In fact, I don't recall ever seeing any reference to hooked rims at all back then. Of course I may have forgotten. I ran them at the rated psi on the straight-sided Fiamme Yellow Label clincher rims, not a superb rim but light. Never had a blow-out until recently when I tried running a 25mm Pasela on them at its rated 115psi. That prompted me to rebuild the wheels with different rims.
In fact, I don't recall ever seeing any reference to hooked rims at all back then. Of course I may have forgotten. I ran them at the rated psi on the straight-sided Fiamme Yellow Label clincher rims, not a superb rim but light. Never had a blow-out until recently when I tried running a 25mm Pasela on them at its rated 115psi. That prompted me to rebuild the wheels with different rims.
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There are probably dozens of ways that it could be standardized that would make good sense so long as it were simple, uniform and informative. What's amazing is that hardly any of the common tire sizing standards are any of those things. You'd think that at some point someone would get it right and then everyone else would jump on the band wagon.
Perhaps the best designation would be this:
Bead Seat Diameter, plus 2 letters designating a width range of tires, for example A = 17mm, B = 19mm, C=21mm, D=23mm, E=25mm, F=28mm, G=30mm, H=32mm, J=35mm, K=38mm, L=40mm, M=45mm, N=50mm, P=55mm, Q=60mm, S=65mm, T=70mm, U=75mm, V=80mm, W=85mm, X=90mm, Y=95mm, Z=100mm+
So a rim might be marked as 622CH meaning that it's designed for a tire that is 21-32mm wide. A bicycle might be similarly marked as 622CK where the frame and components are designed for tires as narrow as 21mm, or as wide as 38mm. By moving to letter sizes, you eliminate the inch/metric issue.
#71
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Avocet TT30 clinchers were made in a 27 by 7/8 and were insanely light and fast rolling folding tyres that are also a little delicate... these are considered to be the best high performance tyre ever made for 27 inch wheels but they are no longer made and the last ones I ever saw were being sold at Harris Cyclery about 6 years ago.
They feel like tubulars on the road... the wheelset they lived on is now on my Garlatti and these are Araya 1W red label hoops of very good quality rolling some Conti 1000's.
I prefer using the ISO designations although I am fluent in French and fractional sizing.
In our collection of bikes I have 349, 406, 451, 520, 559, 571, 590, 597, 622, and 630 wheels and tyres... used to have a few 635 models too.
Back to the 630...
Schwinn and Raleigh both adopted this wheel sizes for a great number of their bicycles save for the top of the line racing models which often came fitted with tubulars and the Japanese also used this tyre size widely and as such, produced a good number of decent rims.
As such there are millions upon millions of bicycles that are still rolling around on these wheels and tyre manufacturers still produce tyres... this last little bike boom brought a lot of these bicycles out of deep storage and our sales of 27 inch tyres has been brisk for several years.
They feel like tubulars on the road... the wheelset they lived on is now on my Garlatti and these are Araya 1W red label hoops of very good quality rolling some Conti 1000's.
I prefer using the ISO designations although I am fluent in French and fractional sizing.
In our collection of bikes I have 349, 406, 451, 520, 559, 571, 590, 597, 622, and 630 wheels and tyres... used to have a few 635 models too.
Back to the 630...
Schwinn and Raleigh both adopted this wheel sizes for a great number of their bicycles save for the top of the line racing models which often came fitted with tubulars and the Japanese also used this tyre size widely and as such, produced a good number of decent rims.
As such there are millions upon millions of bicycles that are still rolling around on these wheels and tyre manufacturers still produce tyres... this last little bike boom brought a lot of these bicycles out of deep storage and our sales of 27 inch tyres has been brisk for several years.
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what about the history of width sizes for 27" tires for mid/upper level bikes?
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
.
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
was 1" always the most narrow available? did marketers go this narrow on their new 'performance' road bikes, or was the substantially fatter 1 1/4" more standard, even for 'racing' type applications?
.
in a thrift store for $15 each, a friend of mine found me a nos mavic ma2 27" wheelset. they're so awesome looking. i put 1" paselas on them, and they look great. but, honestly, 23mm tires would look even better to me. just wondering if even more narrow tires were ever available for 27".
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Like the 27" someday our 700c will be rare
oh no! - the 36 incher:
XXXVI DG concept bike | thisandthat.com.cy
oh no! - the 36 incher:
XXXVI DG concept bike | thisandthat.com.cy
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There were many brands offering hook-bead 27" rims, in both racing and touring widths, and both single- and double-walled styles.
These seemed to have been sold from about '75 to '89 as O.E.M. spec on road bikes.
The 27" Pasela tires in each of the three widths are among the widest 27" tires, almost fully up to their listed widths.
Only the Michelin gumwall (1-1/4" only) seems to measure as wide at 32mm (1.25") on a decently-wide rim.
Older 1" tires were the same width as 25c tires from the same period, up through the 1980's at least.
These 1" and 25c-labeled tires also carried molded-in designations of 20-630 and 20-622, respectively, during the later years of the 27" era.
The molded-in dimension was the more accurate.
I also bought "TurboSport" tires labeled as 27x1-1/4" which carried the (accurate) molded-in size designation of 26-622, made by Cheng/CST and sold by Specialized.
Current standard 1-1/4" gumwalls from Kenda, Cheng, etc. seem to measure 28mm wide on 22-23mm-wide rims after overnight inflation to rated psi.
But on the Varsity, with 28mm-wide steel rims, they measure 31mm after overnight inflation.
Performance sold 27x1" tires up until a couple of years ago that measured 21.5mm on 22mm-wide rims.
The IRC Triathlon was widely distributed in 27x1" width until recently, and was a very sporty tire with a tread thick enough to be called durable.
Current 27x1" Pasela tires measure about 26mm wide on a 22mm-wide rim, fully as wide as tires that some companies label 1-1/8"
Paselas in 1-1/8" size are easily as wide as most 1-1/4" tires from other brands, and I've had clearance issues after this full width took me by surprise.
These seemed to have been sold from about '75 to '89 as O.E.M. spec on road bikes.
The 27" Pasela tires in each of the three widths are among the widest 27" tires, almost fully up to their listed widths.
Only the Michelin gumwall (1-1/4" only) seems to measure as wide at 32mm (1.25") on a decently-wide rim.
Older 1" tires were the same width as 25c tires from the same period, up through the 1980's at least.
These 1" and 25c-labeled tires also carried molded-in designations of 20-630 and 20-622, respectively, during the later years of the 27" era.
The molded-in dimension was the more accurate.
I also bought "TurboSport" tires labeled as 27x1-1/4" which carried the (accurate) molded-in size designation of 26-622, made by Cheng/CST and sold by Specialized.
Current standard 1-1/4" gumwalls from Kenda, Cheng, etc. seem to measure 28mm wide on 22-23mm-wide rims after overnight inflation to rated psi.
But on the Varsity, with 28mm-wide steel rims, they measure 31mm after overnight inflation.
Performance sold 27x1" tires up until a couple of years ago that measured 21.5mm on 22mm-wide rims.
The IRC Triathlon was widely distributed in 27x1" width until recently, and was a very sporty tire with a tread thick enough to be called durable.
Current 27x1" Pasela tires measure about 26mm wide on a 22mm-wide rim, fully as wide as tires that some companies label 1-1/8"
Paselas in 1-1/8" size are easily as wide as most 1-1/4" tires from other brands, and I've had clearance issues after this full width took me by surprise.
Last edited by dddd; 07-14-14 at 06:55 PM.
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On triathlete bikes, that is the 650c's.
Last edited by Road Fan; 07-14-14 at 04:48 PM.