501 or 531 frames

[bigfella]

501 or 531 frames - which are the best in terms of weight and strength?

 

[MacB]

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.

 

[4F]

Here you go http://www.cyclechat.co.uk/forums/showthread.php?t=32646

 

[bigfella]

Cheers, think I will be building 2 bikes then!

 

[Chris James]

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]

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?

 

[MacB]

did you do materials at sheffield chris?

one would hope so, either that or he's been struck down by the 'anorak' disease at some point.

 

[Chris James]

did you do materials at sheffield chris?

Mechanical Engineering, but MacBludgeon knows more about it all than me