# Why did Aluminum come to dominate the MB market?



## EscapeVelo (May 1, 2012)

I rode an early-mid 00s Wal-Schwinn Sidewinder 2.6 FS steel frame with some upgraded parts and was very pleased with the ride. I upgraded the shifters because I didnt care for the grip shifters and had an LBS tune it up. I never got around to it before it was stolen, but I would have gotten wider handlebars to accomodate my broad shoulders.

Anyways, Im sure that others have thought about this and have informed opinions on the question I have posed. Look forward to hearing from the experts.

To round out the question...

Will Carbon Fiber do to Aluminum what Aluminum did to Steel?


----------



## JR 137 (Apr 28, 2012)

It's an interesting question. Reading the archives, people used to like CroMo frames better than aluminum. I guess a couple reasons...

Aluminum doesn't rust the way steel does, hence it's longer lasting
Perhaps manufacturers got better at working with aluminum
But most likely - aluminum is probably cheaper to buy buy and manufacture


----------



## big terry (Apr 22, 2012)

i hope so. i cant afford CF right now. look forward to the day when CF is as cheap as aluminum.


----------



## fireball_jones (Mar 29, 2009)

Aluminum is cheaper and lighter, and it's easier to work with, which allows manufacturers to make all those swoopy frames and fancy full suspension setups.

Once carbon fiber is cheaper, it might replace aluminum. I suspect it will have the same issue titanium did back in the hardtail days, where it was always more expensive to work with than (at the time) steel and aluminum.


----------



## thegooddoctor (May 16, 2012)

My opinion for the short answer is sort of. Carbon Fiber is doing to Aluminum what Aluminum (and Titanium) did to steel. It's happening and if you go into any bike shop, it becomes apparent. When you have a lighter bike that can take the abuse of riding it becomes desireable. This debate will go on and on but I realize many steel and titanium bikes that were produce many many years ago are still either in the garage or being ridden. These metals are tough and strong and can bend. Not so many Aluminum bikes survive the years. Whether through abrasion, fatigue failure (cracks/breaks) or obsolescence a lot of aluminum bikes are being retired/recycled. Carbon bikes are still changing quite a bit to reinforce weak areas, help solve material boundary issues (how to hold metal BB threads to carbon shapes etc) so things don't creak etc. Carbon is a great material because it can be shaped via molds quite easily and strength and suitabillity can have a lot to do with shape. Anyhow, that's my $.02. I'm happy you can still get a great frame out of any of these materials and more. They each have their attributes which go way beyond a forum discussion.


----------



## AndrwSwitch (Nov 8, 2007)

Aluminum has a more favorable strength-to-weight ratio than steel. I'm not sure I agree with the idea that it's cheaper or easier to work with. A lot of the cheapest metal parts are still steel, although nicer steels are more expensive. And high-tech steels get better and better. A boutique builder down the street from me now has a (very expensive) steel frame that can compete head-to-head with aluminum.

Carbon is incredibly cheap. It's a very plentiful element. Carbon fiber cloth is getting cheaper. The layup is still a labor-intensive process, but molding isn't terribly difficult or expensive. 3D weaving is coming along, so I've been imagining a future in which bike frames come out of a 3D loom ready to go into a mold, no layup required. That also means that woven carbon fiber cloth isn't necessary - they'd just need the thread. I think that carbon frames will actually be cheaper than aluminum or steel frames when this process gets worked out. For now, there's still a certain amount of human labor involved in building a carbon frame.

FWIW, the only frame I've broken due to fatigue (or anything) broke at a steel part. Which surprised me, because it was an older frame made of a mix of aluminum and steel, and involved glue. While I'm aware of the lack of an endurance limit for aluminum, I also know how to read a logarithmic scale and I don't think that there's any practical limit on the life of a well-designed aluminum frame. However, "well-designed" is always tricky, and I think that's where the problems bike frames using new technologies come from.


----------



## EscapeVelo (May 1, 2012)

Is an Aluminum frame really lighter than a Cro-Moly Steel frame?

I mean dont you have to use more material in an Aluminum frame, to compensate for aluminums weaknesses?


----------



## highdelll (Oct 3, 2008)

fireball_jones said:


> Aluminum is cheaper and lighter, and* it's easier to work with, which allows manufacturers to make all those swoopy frames and fancy full suspension setups.*




wait what?
easier to work with than?

swoopy frames?
fancy full suspension?


----------



## highdelll (Oct 3, 2008)

EscapeVelo said:


> Is an Aluminum frame really lighter than a Cro-Moly Steel frame?
> 
> I mean dont you have to use more material in an Aluminum frame, to compensate for aluminums weaknesses?


yes, it's really lighter
bigger tubes (diameter - physics in play here) compensate for any weakness


----------



## fireball_jones (Mar 29, 2009)

highdelll said:


> wait what?
> easier to work with than?
> 
> swoopy frames?
> fancy full suspension?


Easier than titanium, and easier than steel if you're shooting for the same weight, and easier to bang out most of the frames you see today on full suspension bikes.

I mean, sure, you can get steel frames with S-shaped 3'' downtubes, they just weigh about 40 lbs.


----------



## EscapeVelo (May 1, 2012)

highdelll said:


> yes, it's really lighter
> bigger tubes (diameter - physics in play here) compensate for any weakness


Right, but doesnt that mean more aluminum than steel is required for any given frame geometry? Or is aluminum so much lighter than steel that even with more material being used in the larger diameter tubes that are required it still produces a lighter frame.


----------



## AndrwSwitch (Nov 8, 2007)

Usually, and yes.

Aluminum is enough less dense than steel that even though more must be used by volume to reach the same yield strength, the finished product is still lighter. Often, aluminum frames are built stiffer. This is to get better fatigue properties, as I understand it, and also something of a reaction to the very flexy aluminum frames that were first introduced. On a mountain bike, IMHO it doesn't matter that much. Your massive off-road tires have a lot more flex than any frame. Some people claim they can feel the bottom bracket torquing around. I guess my comment is that while I wouldn't mind getting more powerful, I hope I never get that heavy. 

You can't draw generalizations across all aluminum and steel frames, of course. The fancy steels are still cro-moly steels, and have extraordinary yield strengths and welding behaviors that mean that not as much needs to be used. Those are the ones that can compete with aluminum, but they're pretty expensive. And aluminum Wal-mart frames can weigh pretty insane amounts. But if you were to compare aluminum and steel frames in similar pricepoints and for similar purposes, you'd generally see lighter frames in aluminum.


----------



## Cayenne_Pepa (Dec 18, 2007)

I don't agree with the "easy to work with" statement either. Ever try to mandrel bend aluminum tubing? You can't...it has to be either extruded, or hydroformed in a bent or non-symmetrical shape. Then, there is also TIG welding aluminum....nothing like tack-welding or using oxyacetylene.

Don't get me wrong - my bikes are still aluminum for the simple reason it's light, stronger than steel(OD tubing) and properly welded joints are tougher against repetitive strain loads than many carbon layups.


----------



## jeffscott (May 10, 2006)

EscapeVelo said:


> Is an Aluminum frame really lighter than a Cro-Moly Steel frame?
> 
> I mean dont you have to use more material in an Aluminum frame, to compensate for aluminums weaknesses?


Yes Aluminium is lighter than steel for bike frames....

Steel is stronger than aluminum.

If you made a steel tube the same diameter and "strenght as an Aluminum tube, the wall thickness would be so thin that a piece of gravel would dent it and ruin it...

So they make steel tubes smaller dia, with a thicker wall...same strength...

Anyway all the pluses and minuses Aluminium is lighter...

Carbon Fiber may take over from aluminum...but not for a while...as more and more things are made from CF (airplanes etc)...the demand increases...the supply of CF is tight right now and will likely be so for the medium term.


----------



## EscapeVelo (May 1, 2012)

Thanks for all the great responses so far!


----------



## EscapeVelo (May 1, 2012)

Main reasons seem to be

weight 
cost
rust

with some nuances here and there.


----------



## vk45de (Feb 1, 2009)

fatter tubing frames also look more sexy


----------



## gmats (Apr 15, 2005)

"In the beginning".......Steel was cheap and easier to work with. Aluminum only came in a few tube sizes and was more expensive to acquire. 

Al was lighter but it took a while for people to learn how to work with the material. It also cost more $$ because it took so much more energy to get the raw stock. Remember the old Vitus road bike frames? They were bonded standard aluminum tubes to lugs. The frames were very noodly. 

So the original mountain bikes were Steel hard tails. The tubes were manipulated and gave a somewhat compliant ride. Remember, there weren't any suspension systems yet. Then people like Cannondale and Klein came along. Originally, the frames solved the problem of a noodle aluminum frame by making the tubes HUGE. Great for pedaling efficiency but hell on the back. Eventually people figured out how to get tubes and pieces made to get the ride to be less harsh. Though Steel and Ti were still the big deal because they generally allowed a more mellow ride. 

Cut to current days. The Al in general has come down in cost because so much more people are using it. Technology has allowed people to manipulate the material into much more desired shapes to be both compliant and stiff. 

Finally, with full suspension frames, you'd prefer a stiffer structure so all the forces go into actuating the suspension system instead of flexing. 

As said above, steel is stronger than Al. Al is 1/3 lighter but weaker. However, with the manipulation of the material, a lighter frame can be made to be as strong as steel. The real problem comes down to how long is the frame expected to survive. Al will generally fatigue sooner than steel unless that is taken into account.


----------



## 29ernb (Mar 20, 2012)

there are different grades of aluminum alloy
7051,6061, 2024 etc what gives strength to alumium is what other metals can be mixed in the alloy.

one thing i don't understand is why trek uses label like alpha platinum, alpha gold, alpha silver to describe there aluminum alloys. how do they compare to 7051 aluminum is what i care about.


----------



## vk45de (Feb 1, 2009)

BTW Moots has a pretty cool materials comparison chart. You have to go to "Why Ti" and look at the PDF at the bottom of the page. It's probably biased but it's a good start.


----------



## DennisF (Nov 4, 2011)

> one thing i don't understand is why trek uses label like alpha platinum, alpha gold, alpha silver to describe there aluminum alloys.


It refers to the fabrication methods used and not to the chemical composition of the alloy. Confusing to use metal names for what are essentially model names.

Silver is single-wall thickness and features "some degree of mechanical forming".

Gold is butted (two wall thicknesses used on a tube) for weight reduction and feature "some degree of mechanical and hydroforming to create more complex industrial designs for even lighter weight"

Platinum is "butted at multiple points", and " feature a high degree of hydroforming to create the most complex industrial designs for the lightest weight".


----------



## gmats (Apr 15, 2005)

29ernb said:


> there are different grades of aluminum alloy
> 7051,6061, 2024 etc what gives strength to alumium is what other metals can be mixed in the alloy.
> 
> one thing i don't understand is why trek uses label like alpha platinum, alpha gold, alpha silver to describe there aluminum alloys. how do they compare to 7051 aluminum is what i care about.


It's a marketing thing. It's one of those everyone else uses "this", we use this which is better. In the end, you have to ask yourself why would a manufacturer spend more $$ for development of an alloy if something that already exists fits the bill? The way I see it, they're finding something "cheaper" that can give almost as good or as good performance at a lower cost (and maybe charge more). Profit margin......


----------



## Haggis (Jan 21, 2004)

I wonder if carbon will be seen as a less eco-friendly material than aluminium, given that aluminium can be recycled many times and the nasty nature of chemical resins.

The surfboard industry has a bad rep for it's effect on the environment...


----------



## EscapeVelo (May 1, 2012)

I found this informative...

*Understanding Bike Frame Materials*


----------



## jeffj (Jan 13, 2004)

EscapeVelo said:


> Will Carbon Fiber do to Aluminum what Aluminum did to Steel?


Only if it becomes easier to manufacture and less expensive to produce with a higher profit margin.


----------



## car bone (Apr 15, 2011)

The real reason they went with aluminum instead of steel is that you can blow balloons out of alu and fit bigger stickers on the frame. Increasing exposure and selling more frames/bikes. Its a marketing strategy that works. And for the general public a curvy full sus fat framed bike with big stickers seems "more better" than a slender or even weak looking ordinary steel or ti double diamond frame.

Carbon pushes this even further so of course it will dominate regardless of how unsuitable it is for certain applications. People buy based on how it looks.


----------



## car bone (Apr 15, 2011)

29ernb said:


> there are different grades of aluminum alloy
> 7051,6061, 2024 etc what gives strength to alumium is what other metals can be mixed in the alloy.
> 
> one thing i don't understand is why trek uses label like alpha platinum, alpha gold, alpha silver to describe there aluminum alloys. how do they compare to 7051 aluminum is what i care about.


I'm guessing their cheapest frames are 60-series, and the most high end ones like 7005, 7050 or or 7075 or similar, whichever can be welded. And thats also the reason they invented "scandium" to make the strongest alu weldable, most scandium frames are 70-series but now with scandium, since the strongest 70 series are not _readily_ weldable. The ones that are are only marginally stronger than 6061 so there is no reason.

I'm still waiting for lithium alu to show up in frames, it has more squish to it, and longer fatigue life, is stronger, more impact resistant, has lower density because of size/weight displacement ratio of the lithium atom. And on top of that I want some scandium thown in there. Lithium alu is mostly used in airframes for fighter jets. Its better all round. But obviously more expensive. Much more. And I think there are massive restrictions on those materials. Very few makers are allowed to but them, like fighter jet makers only.

AAIK 20-series are the first invented high strength alloys from the nazi empire aka "dural" aluminum. These are not really corrosion resistant iirc. There is something to them that are not favorable at least, I think they contain too much copper and that gives them no corroision resistance since copper is the king of corrosion. And they are not really that strong. Could require more expensive ht than 6061 too.


----------



## highdelll (Oct 3, 2008)

car bone said:


> The real reason they went with aluminum instead of steel is that you can blow balloons out of alu and fit bigger stickers on the frame. Increasing exposure and selling more frames/bikes. Its a marketing strategy that works. And for the general public a curvy full sus fat framed bike with big stickers seems "more better" than a slender or even weak looking ordinary steel or ti double diamond frame.


I don't care how much he's had to drink, I'm gettin in the car w/ this guy! prfpfprpfpfprfpawesomeprfapfar


----------



## car bone (Apr 15, 2011)

Its true  

"a marketers dream"


----------



## Ken in KC (Jan 12, 2004)

*Not correct...*



fireball_jones said:


> Easier than titanium, and easier than steel if you're shooting for the same weight, and easier to bang out most of the frames you see today on full suspension bikes.
> 
> I mean, sure, you can get steel frames with S-shaped 3'' downtubes, they just weigh about 40 lbs.


You don't need 3" dia down tubes w steel to get the same structural integrity as you do with larger diameter AL.

And steel bikes with Swoopy tubes don't have to weigh 40 pounds: Inglis & Retrotec Cycles | Quality Bicycles Handmade in Napa, California


----------



## Cayenne_Pepa (Dec 18, 2007)

Yeah, Trek tries to make proprietary their metal, branding them "Alpha SL Alloy." The reality is that it's really heavy crap that makes Trek have one of the highest warranty frame replacements in the industry.


----------

