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ALum 7005 vs Alum 6061(6 posts)

ALum 7005 vs Alum 6061bear
Oct 9, 2001 4:58 PM
how do this alum compare to each other,,I was led to belive that 6061 is better for racing,,I guess it means is stiffer?
weight and cost about the same I think!
re: ALum 7005 vs Alum 6061jacques
Oct 10, 2001 2:00 AM
The numbers 7005, 6061 are industrial designations for two aluminum alloys. They refer to the composition of the aluminum alloy, thus indirectly to properties such as specific weight, strength, corrosion resistance, etc. A website on industrial materials properties will give you the numbers, if you're interested.

The design of the frame has much more to do with stiffness than the aluminum alloy used in its construction.
the site I use is matweb.com look under nonferrous alloys.nmvanzutas
Oct 10, 2001 10:55 AM
well I went and lookedvanzutas
Oct 10, 2001 11:31 AM
I think it is a great question. Looking strictly at the materials and not at the build of the bike. This is all about numbers so don't read this if you don't like numbers.

Concentration of Aluminum 6061...98% 7005...93.3% (differance being 4-5% Zinc in 7005)

Density 6061..2.7 g/cc 7005..2.78 g/cc not much difference.

yield strength 6061..275 MPa 7005..290 MPa
6061 can withstand a little less stress than the 7005 before being PERMANENTLY deformed, you should not reach this point unless there is an accident. I don't know too many people who bend a frame while sprinting.

Modulus of elasticity 6061..69 MPa 7005..72 Mpa
This is the important one. this means that the 7005 is stiffer than the 6061 if both were designed exactly the same.

Fatigue strength 6061..95 MPa 7005..150 MPa
This is the yield strength after 500,000,000 cycles. (I am not sure of the loading in each cycle). this means that the 7005 remains stronger after repeated loading. this is for infinite life though. I am not sure of the initial effects of fatigue.

For a referance her are the same numbers for Reynolds 853 Steel has a modulus of elasticity (stiffness) of 207,000MPa (this does not change from the cheapest to the best steels)
with a density of 7.8 g/cc

Reynolds Titanium has a modulus of elasticity of 125,000 MPa, and a density of 4.42 g/cc

The Reynolds page is http://www.reynolds-cycle.com
go to the Reynolds site it has all the comparisons..vanzutas
Oct 10, 2001 11:47 AM
..in a rational form. it has the aluminum you are looking for plus steel and titanium.

Sorry about posting 3 times in a row. I just keep looking up the materials. Maybe I will post again after looking at some fram builders.

http://www.reynolds-cycle.com/X-100.swf

or just http://www.reynolds-cycle.com The flash site is where I went and it seems a little more up to date.
Great web site but...bear
Oct 11, 2001 2:42 PM
I found the web site super and it answer lots of questions, I would love to get any feed back form personal experiences with bikes build form either 7005 or 6061 if any?
thanks a million guys.