6061, 7000 or 7005
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Splatter Paint
Retrobike Rider
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There was an article recently I read about this, but I can't find it. This page has a similar discusssion, I've quoted an extract from that page.
http://www.pinoymtbiker.org/forum/showthread.php?t=9556
"6061 and 7005 are the two most readily available aluminum alloys appropriate to making bicycle frames. We're also
beginning to see 6066 and 6069 become available from some tubing manufacturers, but only on a very limited basis at this
time. "Scandium" as used frames is actually an aluminum alloyed with a small amount of Scandium, yet is much too
expensive for the general market. There are many other aluminum alloys like 7075 and 2014 that are stronger than both
6061 and 7005, but are not appropriate to making bike frames because they are nearly impossible to weld.
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, but 6061 frames have become more reasonable over the last few years as the technology
and equipment proliferates."
Traditionally high-end frames are 6061-T6 but modern posh aluminium frames use scandium alloy, which is much stronger hence frames can be made with less material and be lighter.
SP
http://www.pinoymtbiker.org/forum/showthread.php?t=9556
"6061 and 7005 are the two most readily available aluminum alloys appropriate to making bicycle frames. We're also
beginning to see 6066 and 6069 become available from some tubing manufacturers, but only on a very limited basis at this
time. "Scandium" as used frames is actually an aluminum alloyed with a small amount of Scandium, yet is much too
expensive for the general market. There are many other aluminum alloys like 7075 and 2014 that are stronger than both
6061 and 7005, but are not appropriate to making bike frames because they are nearly impossible to weld.
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, but 6061 frames have become more reasonable over the last few years as the technology
and equipment proliferates."
Traditionally high-end frames are 6061-T6 but modern posh aluminium frames use scandium alloy, which is much stronger hence frames can be made with less material and be lighter.
SP
In general the material is overplayed. You can make stiff or flexy frames out of anything. Titanium has been cited as an everlasting wonder material, but if made from overly thin tubing or badly welded it breaks.
What is much more important is the frame design and especially geometry.
If you enjoy riding it and it fits your purposes, then that's fine. Most people (me definitely included) could not tell the frame material if they rode it in the dark.
What is much more important is the frame design and especially geometry.
If you enjoy riding it and it fits your purposes, then that's fine. Most people (me definitely included) could not tell the frame material if they rode it in the dark.
It makes no difference to me whether this bike is high, low, in the middle..hamster":jky8e52z said:If you enjoy riding it and it fits your purposes, then that's fine. Most people (me definitely included) could not tell the frame material if they rode it in the dark.
Was just wondering and this was my only point of reference...
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6061 - midrange
7005 - low range
7005 heat treated - high range
That's what I assumed anyway.
7005 - low range
7005 heat treated - high range
That's what I assumed anyway.
MartinYorkshire
Retro Guru
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Hmm. My Kona is Easton Ultralight. I thought this was quite high end but it seems its 7005. Anyone know where it sits in the range? It will affect the bits I hang from it
