Why 27" / 630 mm wheels?
07-14-14, 06:13 PM
#76
curmudgineer
Join Date: Dec 2009
Location: Chicago SW burbs
Posts: 4,417
Bikes: 2 many 2 fit here
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 263 Post(s)
Liked 112 Times
in
70 Posts
The Rigida AL 1320 was one such hooked rim available in 27" in the 70s. Easy enough to make 700C & 27" versions of a given extruded & formed shape, once it is tooled. This rim, and the Michelin Elan (IIRC), mentioned above, are original equipment on my 1978 Motobecane Grand Jubilé.
Regarding the demise of 27" on new bikes, my 1987 Miyata brazenly sports 27" Araya rims that I assume are original.
Regarding the demise of 27" on new bikes, my 1987 Miyata brazenly sports 27" Araya rims that I assume are original.
07-14-14, 06:36 PM
#77
Senior Member
Join Date: Nov 2008
Location: Bay Area, Calif.
Posts: 7,239
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 659 Post(s)
Likes: 0
Liked 7 Times
in
6 Posts
The Rigida AL 1320 was one such hooked rim available in 27" in the 70s.
BTW, the link in the post above gives the outside width as 28mm which is clearly too wide. My recollection is that the 1319 and 1320 nomenclature referred to the inner and outer rim widths (i.e. 13mm inner and 19 vs. 20mm outer).
Last edited by prathmann; 07-14-14 at 06:39 PM.
07-14-14, 09:10 PM
#78
Senior Member
Join Date: Jul 2006
Location: Toronto (again) Ontario, Canada
Posts: 6,931
Bikes: Old Bike: 1975 Raleigh Delta, New Bike: 2004 Norco Bushpilot
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 5 Times
in
5 Posts
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.
07-15-14, 07:53 AM
#79
Senior Member
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".
07-15-14, 08:09 AM
#80
Senior Member
Join Date: May 2008
Location: Fredericksburg, Va
Posts: 9,579
Bikes: '65 Frejus TDF, '73 Bottecchia Giro d'Italia, '83 Colnago Superissimo, '84 Trek 610, '84 Trek 760, '88 Pinarello Veneto, '88 De Rosa Pro, '89 Pinarello Montello, '94 Burley Duet, 97 Specialized RockHopper, 2010 Langster, Tern Link D8
Mentioned: 73 Post(s)
Tagged: 0 Thread(s)
Quoted: 1608 Post(s)
Liked 2,216 Times
in
1,103 Posts
I thought 27 was standard when in high school. My first exposure to 700c was in Frankfurt, Germany, when I purchased a Peugeot and an extra set of wheels with sew-ups.
07-15-14, 11:52 AM
#81
Senior Member
Join Date: Feb 2008
Posts: 1,092
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Yes, but not for many, many years, right? It was a fad with the Tri-geeks.
Some smaller-framed (non-tri-specific) road bikes also are out there, but with the (recent) exception of the Terry Telus 28, your tire choices are usually 23, 23, 23, 23, 23, 23, or 23.
Some smaller-framed (non-tri-specific) road bikes also are out there, but with the (recent) exception of the Terry Telus 28, your tire choices are usually 23, 23, 23, 23, 23, 23, or 23.
07-15-14, 03:47 PM
#82
Senior Member
Join Date: Feb 2005
Location: Pleasanton Tx
Posts: 1,213
Bikes: old,older.and very old
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 31 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
And the 26X1.375 For pre war American L/W bikes or 26X175 for M/W bikes or Schwinn 26X1&3/4
07-15-14, 07:40 PM
#83
Senior Member
Join Date: Jul 2006
Location: Toronto (again) Ontario, Canada
Posts: 6,931
Bikes: Old Bike: 1975 Raleigh Delta, New Bike: 2004 Norco Bushpilot
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 5 Times
in
5 Posts
I think the issue is that SOME tire makers decided that marking a 27mm tire a 28mm, and using the slightly lower weight as a selling feature to the weight weenie set. Then someone else decided to take advantage and sell a 26mm tire as a 28mm, then it becomes a race to the bottom. In some countries like Canada this kind of marking a size larger, could be considered a violation of the acts regarding advertising, and a company could be fined thousands of dollars for pulling this kind of stunt. Canada isn't the only country where a company could get a hefty fine for this kind of nonsense. Moulding a tire differently for different markets does not make economic sense, so some of them don't do it.
