Singlespeed & Fixed Gear - Is Aluminum stronger than Steel?

Sorry, meant to post this in the road cycling forum

I know there are different types of aluminum and steel, but in general, which is stronger?

I'm about 215 lbs. now, but hope to be 190 lbs. by the end of September (through lots of bicycling... I was 240 lbs. when I started this winter).

When I get my next road bike I'm going to get either aluminum or steel, but still am not sure which I should go with. I want something that will be strong and fast, mainly for exercise. I'm definitely not planning on entering races, but I might do some centuries once I drop some more weight.

Are the steel frame Bianchis good bikes (like the Veloce, Eros)... how about the Specialized Allez Cr-Mo? Or should I stick with a something like the Allez Comp with the double-butted aluminum frame?

'Strength' is a design issue, not a materials issue. Generally, any material can be designed as a structure to be 'strong'.

I prefer steel and titanium because they're natural springs and have a resiliant ride feel 'zing' that I like the feel of, and have an infinite fatigue life if cycled under their fatigue limit. Also, I like the aesthetics of them both, being slightly smaller diameter tubes, slightly more traditional looking I guess.

Aluminium and CF are just easier to make and easier to market - that's the only reason they're more prevalent in the market.

Generally, chromoly steel is 'stronger'.
BUT....steel is strong and flexy, this tensile strenght lasts for a long time\ doesn't damage the molecular grain.
For a more ridged strong frame, oversize Alu tubes ( big steel gets heavy ) BUT, this bike will ride hard, and if you bang a tube\ sucking wound ( steel, you got a ding ). Also constant flex in Alu developes micro fractures or a kind of crystalization\ shorter life span.

A guy with real mass, I'd go oversize Alu, me personally, I prefer steel. Or Ti if I could afford.

Oh ****. I should always start my posts 'I ride mtbs only.' Road bikes, I really don't have experience\ informed opinion.

I weigh 190 and i was 200 6 months ago. Most bikes can handle that weight but you might want to go with 700x25 or bigger tires, imho.

Sorry, meant to post this in the road cycling forum

I know there are different types of aluminum and steel, but in general, which is stronger?



I can answer that by asking you which weighs more: a pound of feathers or a pound of steel.

I can answer that by asking you which weighs more: a pound of feathers or a pound of steel.


Are they making frames out of feathers now?

Steel is stronger. Aluminum weighs 1/3 that of steel. It also takes three times as much to get the same strength. Does that help?

I know there are different types of aluminum and steel, but in general, which is stronger?


Steel is much much stronger than aluminum. The modulus of elasticity (a measure of stiffness: 29,000,000 psi for steel and about 10,300,000 psi for aluminum) and the yield point (stress at which a material will deform and not return to its original shape) of steel are far greater than aluminum.

That being said, at your weight you should be able to find a sufficiently stiff and "strong" frame made out of either material. Test ride, test ride, test ride.

BlindRobert,
The numbers you gave are not accurate for all steel or aluminum. Since steel and aluminum can be and is alloyed in thousands of ways the KSI, modulus, yield strength, and elasticity will vary from product to product.

BlindRobert,
The numbers you gave are not accurate for all steel or aluminum. Since steel and aluminum can be and is alloyed in thousands of ways the KSI, modulus, yield strength, and elasticity will vary from product to product.

Actually, the modulus of elasticity of steel is pretty much the same for all alloys because the metals that it is alloyed with are added in minute quantities, aluminum varies more because the alloyed metals are added in proportionately larger quantitiues...which is why I said the modulus of elasticity for aluminum is "ABOUT" 10,300,000 psi.

The horse is close to death but still breathing, so will post this link from the man hizzownself, Sheldon.

http://www.sheldonbrown.com/frame-materials.html