501 or 531 frames

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MacB

Lover of things that come in 3's
531 is the better quality and lighter weight, I don't know the differential though. 500/501 is much easier to come by, much cheaper and, if you have weight to lose yourself, then the frame weight shouldn't be an issue.
 

Chris James

Über Member
Location
Huddersfield
As per the link, 531 is stronger steel so can be built into thinner tubes retaining the same overlall frame strangth.

The weight difference is a bit complicated as it depends on what the butting is on the 501 and 531. All steel have the same density.

For example 531ST main tubes are 1 m and 0.7 m with the butting. But 531C was 08mm / 05mm. So 531C was approx three quarters the weight of a 531ST frame?

501 single butted was 1mm / 08mm and double butted 0.9mm/06mm according to the Reynolds tube constructors guide. So DB was weaker but lighter than SB.

In fact 501DB would only be approx 20% heavier than 531C, so pretty light.

I think 501 was just Cr-Mo, so in which case has a tensile strength of 85,000-115,000 PSI (590 - 760MPa). I believe 531 is around 120,000 PSI, so about 20% stronger than 501.

Reynolds claim 631 has strength of 850MPa and 853 1400MPa.
 

alecstilleyedye

nothing in moderation
Moderator
Chris James said:
As per the link, 531 is stronger steel so can be built into thinner tubes retaining the same overlall frame strangth.

The weight difference is a bit complicated as it depends on what the butting is on the 501 and 531. All steel have the same density.

For example 531ST main tubes are 1 m and 0.7 m with the butting. But 531C was 08mm / 05mm. So 531C was approx three quarters the weight of a 531ST frame?

501 single butted was 1mm / 08mm and double butted 0.9mm/06mm according to the Reynolds tube constructors guide. So DB was weaker but lighter than SB.

In fact 501DB would only be approx 20% heavier than 531C, so pretty light.

I think 501 was just Cr-Mo, so in which case has a tensile strength of 85,000-115,000 PSI (590 - 760MPa). I believe 531 is around 120,000 PSI, so about 20% stronger than 501.

Reynolds claim 631 has strength of 850MPa and 853 1400MPa.
did you do materials at sheffield chris? :rolleyes:
 
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