hey...
does anyone know if there's a significant diff. in weight of butted reynolds 531 tubes and double butted 531?

Others will know more than me about this, but I DO know that not all 531 tubesets were created equal.

531 was made for a LONG time and I'm not a historian...that said, all 531 tubes that I'm aware of have double butted top and down tubes, single butted seat tubes, and straight gauge stays.

EDIT: Based on what others have stated in this thread, straight gauge 531 surely exists. I learned something.

^^^....There was also straignt gage tuesets in .91, .81, and .71mm Weight listed for he heaviest butted stuff in one reference was 2400 grams and the lightest 'SL' tubeset was 1800g.

also, some frames were sold as 531 but had only had 531 main tubes with a 525 rear.

I've weighed a few 531 frames (no fork), with the lightest being 1850g, and the heaviest, ~2200g. 531 from about 1980 and older will mostly likely be heavier than the newer stuff. 531 is lighter than much of the older Columbus steel.

I don't think the butting would make too much difference.

Uh, Sidney, wasn't "SL" a Columbus tube set, not Reynolds?

All 531 is double butted with single butted seat tubes, all Reynolds straight gauge is 501 or 500 which are CrMo not chrome manganese.

Reynolds did make a 500SL tube.

Yes their is a difference in weight thats why they did it. 531 competition is the lightest.

Not acording to my book.

Someone musta screwed up...There is both Reynolds 531 SL and Columbus SL listed in my book.

OK, I learned something today.


Just to be technically accurate Reynolds 531 is a manganese-molybdenum alloy, not chrome-manganese.

I have a Reynolds tube order form from about 10 years back and there is no straight gauge 531 tubes listed. No doubt Reynolds will make what ever tubes a manufactuer desires (for a fee of course), but I can't help but think that straight gauge 531 is quite rare.

^^^....My book is from 1974, and list 3 straight gage tubesets in 531. The stuff has been arond since the mid '30s IIRC.

Well, between 1974 and the mid-90's (Nessism's order book) the bike market changed a lot and the demand for straight gauge steel tube sets pretty much disappeared. I'm not surprised the later order form doesn't offer them.

There were many different kinds of 531 tubesets. There was a straight gauge 531 called 531 tubing; for more information on some of the 531 tubesets go here: https://www.classicrendezvous.com/Bri...ds_gallery.htm

There was also not listed in the web site above 531st for touring, 531t for tandem, 531os for oversize tubing, 531cs for custom sport, 531pro which was similar to 531c. The lightest weight tubing was the c and pro followed by the cs.

The weight difference between the regular butted and regular dble butted was maybe 1/2 pound.

Wow, sounds like an "old-timer" discussion. Hey, I wonder if any custom-frame builders ever "mixed" different tubesets for certain sizes and types of bicycles?

I wonder what the numbers "8 5 3" mean on newer tubing?

At one time, I thought "tube numbering" had something to do with ANSI steel/alloy identification standards.

In the past makers used to mix tube sets all the time. The most common was the use of Columbus SP downtubes (heavier wall thickness) in larger frames of otherwise SL tubes. I suppose there was nothing to prevent using a mix of Columbus and Reynolds tubing in one frame but I don't recall hearing of anyone who did.

I'm pretty sure the tubing set numbers, 531, 725, 853, etc. are contrived labels having no relationship to the ANSI/AISI alloy family numbering system.

It can if it's a 4 digit # like 4130 cromo. ... 7005 and 6061 are specific aluminu alloy types...Ti is identified as CP, 3/2.5 or 6/4. Now manufacturers of steel tubing just make up numbers as they go along. 631 and 853 are the same air hardenting alloy,but 853 is heattreated for more strength. 753 was the heattreated version of 531. Columbus doesn't even use numbers.

I have a frame with a decal that reads 'Reynolds 501 Cromalloy-M Fork Blades, Stays & Butted Frame Tubes'

A lot of current manufacturers mix tube sets. DMR with a 520/4130 bike and Waltworks who uses quite a few different tubings come to mind right away.

Reynols 531 was made in what Reynolds called plain guage tubing, which was straight guage. They also made double butted tubing, and single butted tubing for seat tubes, chainstays. and forks. Single butted tubing was used in forks and chainstays because the tapering process thickened the tube walls on the tube ends, negating the need for a butt there.

If anyone questions this, buy this and find out for yourself.

https://cgi.ebay.com/Reynolds-531-but...QQcmdZViewItem

i want that. have no idea what i'd do with it, but hey.

They still mix different steel tubing in frames. I've found plenty of custom shops mixing 853 used in the main tubes with 753 in the stays etc. Rivendell uses several different tubes from other manufactures in their bikes. This can be found in many custom made shops. BUT, back when 531 was being made, few custom shops mixed with other tubes, they just used all 531 and sometimes 501 for the stays and forks if they were making a lower grade frame.

Not unless they are silver brazing it,and IIRC 753 is out of prod****ion.

Yes, Reynolds made butted 501 tubing also, not just straight gauge.

I get those numbers mixed up, let's see, I think it's 725? I know it's 700 something! I could look it up but I'm too lazy.