# Aluminum - 6061 vs. 7005?



## SlowMo

Looking at getting a cross bike. The two I've narrowed it down to are completely different in regards to specks, including the frames. 

Is there a big difference between these - 6061 vs. 7005? What is it?


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## russotto

There's differences in working with the material (6061 needs heat treating), but as far as the end product goes, likely not.


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## wim

As russotto said, these numbers refer to differences in the chemical composition of the two aluminum alloys. Once shaped into tubes and welded into frames, there's no way a rider could tell 6061 from 7005. Concern about these numbers would be akin to concern about the trees from which the 2 x 4s were cut for your new home.  

Still, good reading at the links if you like to get to the bottom of things.

http://en.wikipedia.org/wiki/6061_aluminium
http://en.wikipedia.org/wiki/7075_aluminium


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## CleavesF

I disagree. You can tell the difference as I own both a 7005 and 6061 frame. 

This is as legit as saying you can tell the difference between Reynolds or TruTemper steel or hell, cheap steel.

I know you all know what cheap crap aluminum feels like when you ride it!


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## Dajianshan

I think I read somewhere that the difference was in how the tubes are bonded together. The 6061 was a slightly weaker bond and that might be an issue in cyclocross. The 6061 is easier to cut and machine so it may be preferred to lower costs. The 7005 is more difficult to work with, but stronger, maybe more expensive for the components. It may also affect ride and feel. That said... I know Fuji uses 6061 and people seem satisfied with their Cross Pro and Cross Comp (well speced rigs). Anyway... that's what I remember.


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## wim

*?*



CleavesF said:


> I disagree. You can tell the difference as I own both a 7005 and 6061 frame.
> 
> This is as legit as saying you can tell the difference between Reynolds or TruTemper steel or hell, cheap steel.
> 
> I know you all know what cheap crap aluminum feels like when you ride it!


No doubt. But that difference has absolutely nothing to do with the chemical composition of the aluminum alloy that was used in making the tubes of your two frames.

I don't understand the "cheap crap aluminum" thing—are you referring to one of the two alloys in question?


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## Dajianshan

Maybe this will help

http://www.eastonbike.com/downloadable_files_unprotected/r&d_files/R&D-01 Al Alloys.pdf


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## wim

Dajianshan said:


> I think I read somewhere that the difference was in how the tubes are bonded together. The 6061 was a slightly weaker bond and that might be an issue in cyclocross. The 6061 is easier to cut and machine so it may be preferred to lower costs. The 7005 is more difficult to work with, but stronger, maybe more expensive for the components. It may also affect ride and feel. That said... I know Fuji uses 6061 and people seem satisfied with their Cross Pro and Cross Comp (well speced rigs). Anyway... that's what I remember.


The "weaker bond" stories with 6061 rest on he fact that 6061 loses strength where it has been welded. But after the required expensive and precisely controlled heat treatment, 6061 regains its strength in the weld zones.

On the other hand, 7005 requires very little heat-treatment after welding. That makes it easier and less expensive to use for bicycle frames. With 7005, there's no need for a complex heat-treating facility and the personnel to run it properly.

None of this matters to the rider—one alloy is as good as the other with everything else being equal.


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## QQUIKM3

*I'm an engineer, trust me. .*



wim said:


> The "weaker bond" stories with 6061 rest on he fact that 6061 loses strength where it has been welded. But after the required expensive and precisely controlled heat treatment, 6061 regains its strength in the weld zones.


You hit it on the head. 6061 requires a lot of post weld heat treatment, and is easier to work with than 7000 series aluminum.


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## SlowMo

*Good information...*

Judging by the responses, I'm going to say that I'm probably not going to see a noticeable difference between the two. I would like to know what differences are noticeable by the user that has both of these, if you wouldn't mind? I realize there's a substantial feel with steel vs. aluminum vs. carbon; but how could it be noticeable with aluminum, unless you're using a different setup? (IE: fork, wheels, etc.) If everything was set up identical (rigid, same wheelset), how big of a difference could that truly be?

Thanks for the posts. Very much appreciated.


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## russotto

wim said:


> Still, good reading at the links if you like to get to the bottom of things.
> 
> http://en.wikipedia.org/wiki/6061_aluminium
> http://en.wikipedia.org/wiki/7075_aluminium


Note that that last link is 7075, not 7005. 7075 isn't used for frames (the wiki page says it's "not weldable" which would be the main reason for that); I think it's used for chainrings though, as its one of the hardest Al alloys.


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## wim

russotto said:


> Note that that last link is 7075, not 7005. 7075 isn't used for frames (the wiki page says it's "not weldable" which would be the main reason for that); I think it's used for chainrings though, as its one of the hardest Al alloys.


Sorry about that. Here's a link to the whole shidload of aluminums, including 7005. I still stumble over numbers. I grew up speaking German. In that language, you would say the number '75' as 'fünfundsiebzig' which literally translates into 'five and seventy.' See how easy it is to get confused if English wasn't your crib language?  

http://en.wikipedia.org/wiki/Aluminium_alloy


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## MaestroXC

CleavesF said:


> I disagree. You can tell the difference as I own both a 7005 and 6061 frame.


And is the frame geometry, not to mention tube thickness and butting the same between both frames? Same components? 

I disagree with your disagreement.


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## CleavesF

So you're gonna tell the Steel guys they can't tell the difference between different alloys of steel? 

You gotta be kidding me.


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## russotto

You could probably tell the difference between 6061 Aluminum and 1000-series Aluminum, if anyone was fool enough to make bikes in the latter. But between 6061 and 7005? Forget it. They have essentially the same modulus of rigidity and modulus of elasticity. Same density, too. They have similar hardness (not that you'd notice that either). 7005 is somewhat stronger (5% greater yield strength), but not enough that you could use significantly thinner tubes.


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## MaestroXC

CleavesF said:


> So you're gonna tell the Steel guys they can't tell the difference between different alloys of steel?
> 
> You gotta be kidding me.


You didn't answer my question, and no, I'm not kidding you

I'm questioning your (or anyone's) ability to distinguish the characteristics of the frame material independent of the other details of its construction. You aren't comparing apples to apples (ie geometrically identical frames made of identically shaped and butted tubes), and so I think you're drawing improper conclusions.

Don't worry about it, you aren't alone.


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## ste2ko

*Cube LTD Race tube material*

Hi guys I've recently purchased a Cube LTD Race 2011 mtb and bought it believing it to be made from 7005 double butted aluminium, every web site selling this bike also describe it as brig made from this material, upon inspection of the bike at the back of the tube it says 'alu superlite 6061 double butted RFR Geometry' I'm concerned because I think this may be false advertising or a general misprint on all the various websites including the Cube website. Is this material the same and is 7005 better/worse than 6061?

Any help would be much appreciated.

Cheers

Steve


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## Kontact

CleavesF said:


> So you're gonna tell the Steel guys they can't tell the difference between different alloys of steel?
> 
> You gotta be kidding me.


No one is kidding you. The alloys limit what you can safely do with a material, not how they ride. You can't safely make as thin a tube out of one steel as another, but if you do make them to exaclty the same dimensions the tubesets ride identically.

If two aluminum (or steel, or titanium) frames are built with identical shaped tubing and joints, the air temperature and paint thickness are going to have more difference in ride quality than the specific alloy.

Also, calling 6061 "crappy" just demonstrates that you don't understand the point of alloys. The numbers don't reflect a scale of quality. You can do things with 6061 that you can't do with 7005, and vice versa. 2000 series aluminum is used for many cycling parts as well, because it works much better for certain applications and fabrication methods than other alloys.


In any case, arguing about the relative properties of aluminum - a material largely relagated to entry level bike frames - is a waste of time. If you were truly concerned about ride quality you wouldn't be riding an aluminum frame (possible exceptions - Cannondale CAAD10 [made of 6069] or Pegoretti).


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## CleavesF

I never said 6061 is crappy. And I understand Alu in general is a harsher ride quality, but it's really not THAT bad as people make it out to be. 

Yes, there are too many variables to completely isolate and make the scientific method work here with bicycles with diff. geo, material and road/line you'll ride on. 

All I'm saying is... if you can feel the difference between 853 and 520 Reynolds... why would there be any doubt that there isn't any diff. b/w 6061 and 7005. 

Yes, I'll admit, the difference is probably in my head. And the diff between Alus is to my perception much less than say between steels. But c'mon... you have a admit that different carbon construction makes a difference. Mono vs Uni layup is drastically different. 

Now lucky for us, alu is much less complex... but 6061 vs 7005 vs Scandium is always going to exist. To tell people they shouldn't buy a bike because the "Alu upgrade" is a waste is no different than telling those owning carbon frames they should have bought the Asian Ebay Knockoffs.


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## Kontact

CleavesF said:


> I never said 6061 is crappy. And I understand Alu in general is a harsher ride quality, but it's really not THAT bad as people make it out to be.
> 
> Yes, there are too many variables to completely isolate and make the scientific method work here with bicycles with diff. geo, material and road/line you'll ride on.
> 
> All I'm saying is... if you can feel the difference between 853 and 520 Reynolds... why would there be any doubt that there isn't any diff. b/w 6061 and 7005.
> 
> Yes, I'll admit, the difference is probably in my head. And the diff between Alus is to my perception much less than say between steels. But c'mon... you have a admit that different carbon construction makes a difference. Mono vs Uni layup is drastically different.
> 
> Now lucky for us, alu is much less complex... but 6061 vs 7005 vs Scandium is always going to exist. To tell people they shouldn't buy a bike because the "Alu upgrade" is a waste is no different than telling those owning carbon frames they should have bought the Asian Ebay Knockoffs.


You used the term "crap aluminum" several posts ago. What where you referring to if not in 6061?

Also, you seem to be confusing several different things:

853 and 520 are tubesets. Tubesets aren't just different in alloy; they vary by diameter, wall thickness, butt length, heat treatment and sometimes shape. And if you were to make two bikes out of dimensionally identical 520 and 853, they would ride identically. But where are you going to get an 853 tubeset of identical dimensions to 520? Reynolds isn't going to waste their 853 process on 520 dimensions. 853 and 631 or 753 and 531 are the same alloys, but made into different tubesets.

6061 and 7005 are alloys, not tubesets. A block of 6061 doesn't act any different than a block of 7005 - you have to make it into something, first.


Finally, your reference to Ebay framesets means that you are also confusing frame quality with tubeset quality AND alloy quality. You can make a great frameset from a relatively modest tubeset, and you can make a shoddy frame from great tubing. One does not dictate the other. An ebay frame might be good, or might not - the reason we buy name brands is that the brand has a reputation which has been earned, while a no-name does not. But that doesn't mean a no-name can't exceed the quality of Trek, just that you have no reason to expect that it will. Some of those Ebay bikes were built by companies that contract with name brands, so they may well be just as nice.

Bicycles are more than the some of their parts. Please don't confuse what they are made out of with how they are made.


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## Camilo

Pretty seamless argument for a 1 1/2 year thread jump!


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## Special Eyes

I believe the alloy you are referring to is 7075, not 7005. And the heat treatment condition spec is a factor, too. There is 7075-T6, 7075-T73 and 7075-T7351. Probably other conditions, too. It's quite different from the more common 6061-T6 or 6061-T6351.


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## terbennett

Kontact said:


> In any case, arguing about the relative properties of aluminum - a material largely relagated to entry level bike frames - is a waste of time. If you were truly concerned about ride quality you wouldn't be riding an aluminum frame (possible exceptions - Cannondale CAAD10 [made of 6069] or Pegoretti).


I question this because there are a lot of capable aluminum frames. Remember that just 6-7 years ago, most highend bikes were still made of aluminum. The issue isn't that modern aluminum frames are entry level frames; The issue is more that most aluminum frames today are equipped with entry-level components. There's a guy on the Felt forum that bought the entry level, Sora-equipped F95 and upgraded it with full Dura Ace group. He shaved off a lot of weight and he said that the ride difference is like night and day. There are many nice aluminum frames out there but the industry wants to push carbon- leaving aluminum as an option for entry-level bikes. A CAAD 9 has a 6061 frame and it has a nice ride. In your defense, a CAAD 10 and Pegoretti are great examples that aluminum bikes have good ride qualities but I would like to add Tsunami to that list as well.


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## Kontact

terbennett said:


> I question this because there are a lot of capable aluminum frames. Remember that just 6-7 years ago, most highend bikes were still made of aluminum. The issue isn't that modern aluminum frames are entry level frames; The issue is more that most aluminum frames today are equipped with entry-level components. There's a guy on the Felt forum that bought the entry level, Sora-equipped F95 and upgraded it with full Dura Ace group. He shaved off a lot of weight and he said that the ride difference is like night and day. There are many nice aluminum frames out there but the industry wants to push carbon- leaving aluminum as an option for entry-level bikes. A CAAD 9 has a 6061 frame and it has a nice ride. In your defense, a CAAD 10 and Pegoretti are great examples that aluminum bikes have good ride qualities but I would like to add Tsunami to that list as well.


Why would changing components make the ride better?

I was not saying that aluminum frames are bad. I am saying that aluminum lacks some of characteristics necessary to make a great riding frame. It just lacks that spring that other materials have. For certain uses, this might not matter. But if we are talking dream road bikes - capable of riding crits AND centuries, I think the material is a compromise. You can make a stiff bike from aluminum, or a soft riding one, but you can't combine those features very easily and get something that feels efficient.

What was popular 6 years ago, and what is popular in general, is a little beside the point. The fact that so many companies stopped making carbon bikes for much of the '90s only tells us that there were manufacturing issues that needed to be overcome. Aluminum filled that gap.

There are master builders working in almost every material, but Peg is the only guy like that working in aluminum (on one model). I think there's a reason for that aside from customer preference.


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## Peanya

Camilo said:


> Pretty seamless argument for a 1 1/2 year thread jump!


Especially considering that the bump is spam. :blush2:


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## Lionvista

Well, I think the best part of the whole thing was the analogy that referred to being concerned with which kind of tree the 2x4s in your house came from.


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## Nerdsftw

I think they are similar but 7005 is cheaper to make.


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## box handler

Look, both are high quality, as aluminum alloys go. I can tell you that I have experience with different alloys not in frames but in handlebars (FSA Omega in 6061 and 3T Ergonova Pro in 7075) and there was a subtle but noticeable difference in harshness, the 3T 7075 winning out despite the FSA's better shape (for my hands, at least). I'm not sure how much this helps, except to say that 6061 can be rather unforgiving. But, there is also a lot more that goes into a frame's ridability than material (just look at Cannondale's mastery of aluminum).


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## ean10775

I think you'd probably have to have the exact same bike with the same geometry, setup and components to make and accurate assessment of the differences between the two materials.


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## Camilo

box handler said:


> Look, both are high quality, as aluminum alloys go. I can tell you that I have experience with different alloys not in frames but in handlebars (FSA Omega in 6061 and 3T Ergonova Pro in 7075) and there was a subtle but noticeable difference in harshness, the 3T 7075 winning out despite the FSA's better shape (for my hands, at least). I'm not sure how much this helps, except to say that 6061 can be rather unforgiving. But, there is also a lot more that goes into a frame's ridability than material (just look at Cannondale's mastery of aluminum).


I would say that the only conclusion that could be drawn from your experience is that the 3T handlebars felt better to you than the FSA's. I dont' think we can draw conclusions on the material since the bars weren't identical. Note I'm not disputing you felt a difference, but I really don't think you could draw conclusion that the material was what made the difference, imho.


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## Kontact

Different alloys of the same material don't "feel" different. They act the same until you flex them to the point of bending or cracking.


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## orange_julius

Camilo said:


> I would say that the only conclusion that could be drawn from your experience is that the 3T handlebars felt better to you than the FSA's. I dont' think we can draw conclusions on the material since the bars weren't identical. Note I'm not disputing you felt a difference, but I really don't think you could draw conclusion that the material was what made the difference, imho.


Yes, exactly. The thread dredge has basically gotten us 'round to having to point out yet again that it is not possible to compare apples and oranges. Not when they don't even have the same shape.


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## Darton

6061: easy to weld, "pre-tempered"
7005: tougher than 6061 so need less, costs more, not corrosive-resistant, harder to work with


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## BacDoc

Lionvista said:


> Well, I think the best part of the whole thing was the analogy that referred to being concerned with which kind of tree the 2x4s in your house came from.


That is a great analogy. I use wood pallets to build trail features on a private MTB trail and the type of wood used in pallets varies quite a bit. Some wood will handle lots of weight and last for years and others will flex, buckle and fall apart in months.

Some might be able to feel the diff in frame material - the hard core cross guy who hammers ridiculous terrain will probably be able to feel a diff compared to the rider on smooth paved surface.


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