Reynolds 531 refers to the ratio of the major elements. Myth?

[Yellow Saddle]

The info is from "The Custom Bicycle, Michael Kolin and Denise de la Rosa", the chapter about Bicycle Tubing page 24.
Quote “Reynolds 531 is a manganese-molybdenum tubing the 531 refers to the ratio of the major elements it contains.”

Maybe, the book is incorrect.............

Just maybe.

 

[Yellow Saddle]

It'd still be 501 dude to the O down the middle of the tube.

No no no no. That's 5o1 you are thinking of. 501 is the ovalised tubeset. Much rarer.

 

[Gravity Aided]

Still about the best riding steel out there, IMHO.
531 is just the smiles per mile.