The nature of Peugeot 531 tubing

[Ajoten]

I briefly owned a very nice Peugeot 531 frame that was of indeterminate model and age but I roughly guess early 90s. It was what I hoped of that metal in weight, surprisingly light. However I ended up swapping it for a 1982 Pug of the same material that is distinctly heavier. A bit disappointing, although weight was never a criterion when buying.

I assume a proper brand like Peugeot wouldn't go about putting superior stickers on inferior frames? Is 531 intrinsically variable, or are there different grades that manufacturers could use? Does year of manufacture make any difference at all (like fine wine...)?

 

[cce]

Some frames are all 531, some are only part 531. You only need one tube to have a 531 sticker. The difference between a 531 seat tube in a frame made of lesser materials and a full 531 frame could be marked

There are different grades of 531 too, although these are usually clearly marked as they're an upselling point

 

[pigman]

Re:

531 competition is a lot lighter than the old 531 double-butted which would have been around in '82.
You also need to ask whether the newer frame is 531pro, which is lighter than 531C
And the level of chrome plating adds weight too.

 

[Pionir]

It's surprising how variable the fork weight can be. Cro-mo forks matched with a "3 tubes" 531 frame can be a kilo whereas a 531pro fork can approach nearly half that

 

[hamster]

531 is the alloy which has remained the same over time.
However the tube sizes, thicknesses and butting profiles have changed significantly over the years.
The label style is a huge help in working out exactly what you have (along with a set of scales). A typical full 531 frame will be in the region of 1.8-2.0kg, depending on size.