6061 vs 7005 aluminium

[Aab]

Hej, how would you compare 6061 aluminium with 7005 aluminium frames?
Just remembered how years ago one friend gave compliments to my bike and its 7005 frame. He said it's pretty rare to see such frame.

[Aab]

Since my post I learned that 7005 frames are more difficult to manufacture and probably that is the reason. Overall 7005 is less superior than 6061 aluminium and can feel more rough when riding on such a frame but it is meanwhile stronger, more durable and more expensive.

[IgorCvetkovski]

(09-05-2019, 09:38 AM)Aab Wrote:  Hej, how would you compare 6061 aluminium with 7005 aluminium frames?
Just remembered how years ago one friend gave compliments to my bike and its 7005 frame. He said it's pretty rare to see such frame.

6061 (aluminum/magnesium/silicon alloy) is generally considered superior to 7005 (aluminum/zinc alloy), though in some
respects 7005 can be stronger. The tensile strength of 7005-T6 is 51,000 psi vs 45,000 psi for 6061-T6. Yield strengths are
42,000 psi vs 40,000 psi, respectively. Tensile strength measures the amount stress required to cause complete failure,
while yield strength measures the amount required to deform the material. The problem is that the ratings are measured on
solid aluminum. When to comes to frames, the greatest differences in strength will come from the quality of the welds,
selection of tubing shapes and thicknesses, and the overall design of the frame.
The truth is, in terms of the forces that a bicycle frame is typically subjected to the base material strength differences
between 6061 and 7005 alloys are fairly negligible. You are unlikely to ever put more than a fraction of the stress on your
frame that would cause it to reach those force levels. Nevertheless, the 7005 is the stronger of the two in those respects
(6061 is superior in stretch resistance, but again those figures are far outside of the realm of real world use). So why do I
say that 6061 is considered to be the superior material for making bike frames?
As mentioned by several posters, 6061 is easier to manipulate making butting and tube shaping like ovalizing and tapering
less costly. On the other hand, 6061 requires precise liquid cooling as part of the heat-treatment process that all aluminum
bikes frames must undergo after welding, whereas 7005 can be air cooled. The bottom line was touched upon by an earlier
poster, but is essentially that we can execute a better and lighter design easier with the 6061. Due to the degree of
manipulation, and the liquid quenching, a 6061 frame is typically more expensive to produce. It used to be a considerable
difference just a few years ago,

[ReapThaWhirlwind]

6061 is basically going to be the 'bare bones' quality aluminum.

7005 is stronger, and so would be the higher quality aluminum for bike frames, especially when you consider its crash survivability.

[SPINMAN]

(11-24-2022, 12:22 PM)IgorCvetkovski Wrote:  

(09-05-2019, 09:38 AM)Aab Wrote:  Hej, how would you compare 6061 aluminium with 7005 aluminium frames?
Just remembered how years ago one friend gave compliments to my bike and its 7005 frame. He said it's pretty rare to see such frame.

6061 (aluminum/magnesium/silicon alloy) is generally considered superior to 7005 (aluminum/zinc alloy), though in some
respects 7005 can be stronger. The tensile strength of 7005-T6 is 51,000 psi vs 45,000 psi for 6061-T6. Yield strengths are
42,000 psi vs 40,000 psi, respectively. Tensile strength measures the amount stress required to cause complete failure,
while yield strength measures the amount required to deform the material. The problem is that the ratings are measured on
solid aluminum. When to comes to frames, the greatest differences in strength will come from the quality of the welds,
selection of tubing shapes and thicknesses, and the overall design of the frame.
The truth is, in terms of the forces that a bicycle frame is typically subjected to the base material strength differences
between 6061 and 7005 alloys are fairly negligible. You are unlikely to ever put more than a fraction of the stress on your
frame that would cause it to reach those force levels. Nevertheless, the 7005 is the stronger of the two in those respects
(6061 is superior in stretch resistance, but again those figures are far outside of the realm of real world use). So why do I
say that 6061 is considered to be the superior material for making bike frames?
As mentioned by several posters, 6061 is easier to manipulate making butting and tube shaping like ovalizing and tapering
less costly. On the other hand, 6061 requires precise liquid cooling as part of the heat-treatment process that all aluminum
bikes frames must undergo after welding, whereas 7005 can be air cooled. The bottom line was touched upon by an earlier
poster, but is essentially that we can execute a better and lighter design easier with the 6061. Due to the degree of
manipulation, and the liquid quenching, a 6061 frame is typically more expensive to produce. It used to be a considerable
difference just a few years ago,

As someone said, "it's only as strong as the weakest link," so your point of the quality of the welds is the main point in deciding on aluminum. It seems like the best course is buying a frame from a reputable manufacturer and do your own build. 6061 or 7005 as you pointed out is somewhat negligible aside from comfort, perhaps. Starting my research for a new build now. I'll let you know.