Jim,
Over the past several years I've seen a number of responses to inquiries like yours from people currently working at Reynolds. I suspect that some of those employees may have been running around in 3 corner pants during the 70s! ;-)
In the mid 70s I had a copy of Reynolds' "Stock List" that had all of the variations of Reynolds 531 bicycle tubing that they made as "standards".
They weren't necessarily the tubes that they stocked but what you could order direct from them. Reynolds had a 100 set minimum order which amounted to enough tubes to build 100 frames. You could specify the tubing variations that you wanted and they were made to order.
For lesser quantities you had to go through one of their "Stockists" in the UK like Holdsworth and others.
Reynolds used to have some recommended tubing combinations such as "Club", "Sprint", "Tandem" and so on. Some of the folks from the UK may chime in here with additional information.
In the mid 1970s Reynolds offered 2 boxed sets of tubes. The "standard" 531 was was approximately equivalent to what they later called their 531C tubing.
The lighter weight 531SL (for Super Light) was close to 531P or Professional tubing.
The 531SL sets had the then new "Continental Oval" fork blades (which had a terrible shaped bend). They were similar in shape at the top to Columbus fork blades.
The 531 characters on Reynolds 531SL transfers were red while the word Reynolds across the 531 was green. They also had "SPECIAL LIGHT WEIGHT" or "EXTRA LEGERE" in red letters on the transfer. That's probably the RED transfers that you mentioned.
Reynolds "butted" seat tubes were single butted. The thicker end was supposed to go into the BB shell. That's not to say that someone could have accidentally put the seat tube in upside down or used a double butted down tube either intentionally or by accident.
Here are some standard Reynolds seat tube wall thickness dimensions in millimeters from a 1974 publication. The tubing was available in Imperial (inch) or Metric (French) diameters:
753 0.71/0.376mm 531SL 0.71/0.56mm
Standard single butted 531 1.02/0.71mm 0.91/0.61mm 0.81/0.56mm
Straight gage 531 0.91mm 0.81mm 0.71mm
They also made seat and top tubes with wall thicknesses reportedly as thin as 0.3mm that were used for many years by some of the French constructeurs.
Reynolds sold some boxed sets of first generation 753 tubing too. These were "supposed" to only be available to builders who had submitted test samples to Reynolds for certification. They were only available in metric tube diameters.
There were probably additional size variations plus as you mentioned the tubes could have been reamed to a larger size along the way.
My guess and experience is that the closest some seat tubes ever came to a reamer was a hand tool on the final assembly line used to clean out excess paint overspray! ;-(
Chas. Colerich Oakland, CA USA
J R wrote:
> A few years ago I contacted Reynolds in regards to this very question. The imformation in regards to tubing thicknesses on my site was reviewed by a Reynolds representative and the information on the gazelle sire was originaly sent to me by the same Reynolds rep and i subsequently forwarded to the proprietor of the Gazelle site. Reynolds' representative said there could be any number of seatpost sizes primarily due to 2 reasons. Tubes could be either Imperial or French diameters and the wall thicknesses could be either conventional DB* or SL. In reality seat tubes were single butted, green label seat tubes were 1.0/0.7 and red label seat tubes were .7/.55. That gives us 4 potential seat post sizes: Meteric w/ green label or red label and Imperial with green label or red label.
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> On top of that each manufcturer would/could ream out the tubing as needed which in turn opens up the potential for additional seatpost sizes.
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> In regards to gauge, its my understanding that both Imperial and French tubing have the same wall thickness, the difference is in the overall diameter (gauge).
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> Its also importnat to never assume that decal language is indicative of the tubes being Metric or Imperial. Decal language is simply that, the language the decal was printed in, it has nothing to do with anything else. The decal pictured on my website should be considered a 'representative' sample.
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> Jim Ruggieri aka 'miamijim' on the bikeforum
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> Tampa, FL USA