[Alaska Mike]

Remember Newton's third law? Every action has an equal and opposite reaction? If the frame flexes, it will flex back. Where does the energy go? Not into heat, so into the return flex of the frame.

Yes, but it depends on how the frame flexes under load- which comes back to how the carbon is laid down.

If a frame deflects laterally, it will bounce back laterally, wasting some of the input energy intended for forward propulsion.

 

[tlg]

very few engineers in the bicycle industry are doctorates. The industry can't afford to pay them.

Really? I'd imagine every competitor in the aero game has a PhD or two.
Heck, Specialized could afford to build their very own wind tunnel. Recruited Chris Yu, a PhD in the field of High Fidelity Flow Simulation

Nathan Barry, one of Cannondale’s team of design engineers, is an aero specialist and has a background in aerodynamics, specializing in bicycles — he’s published papers and his PhD on how to analyse real world aero for bicycling .

Canyon head of R&D is Dr. Michael Kaiser

 

[Coolhand]

FWIW- steel was better for low production craftsmen/artists, carbon fiber was better for aero, lightness, ride quality, fatigue life, ease of production scaling, and design flexibility, and Aluminum took over the low end. Ti didn't have much left. Ti is like Campy, a sub-optimal choice made because of what it is to the buyer. Ti isn't a logical choice, its an emotional one for the buyer.

Also FWIW, in my opinion the Ti bikes I have owned were no better than the Steel bikes I owned, nor decidedly better than the CAAD5 I owned (but were way more expensive). The Ti bikes were better than the early carbon bikes I owned, and not nearly as good as the last two generations of carbon bikes I have owned.

 

[Jay Strongbow]

That's if you buy that "tuning" really accomplishes anything but market speak. To me, a frame is supposed to be rigid and is a structure to enable the attachment of components in the proper locations. Tires and tire pressure has more effect than frame material. People say that steel rides better, Ti rides better, carbon fiber is too stiff; it's all BS.

I moved everything from one frame to another, kept using the same PSI, so the only variable is the frame and I disagree strongly.
I'd agree it didn't necessarily have anything to do with what the frames were made of but the implication that frame doesn't matter at all I find absurd.

 

[Lombard]

Wow...this is roughly the equivalent of bring a wooden spoon to a gunfight.

Or this:

https://www.youtube.com/watch?v=nNh51G84WZY

Of course. That’s how it works. Someone making a claim (or accepting a claim) should support that claim with research.

Pot meet kettle.

Weren't you the guy who claimed that quick release was vastly superior to thru-axle for disc brake bikes? And IIRC, you also claimed that post mount was superior to flat mount.

Hello Waspinator!

 

[taodemon]

I moved everything from one frame to another, kept using the same PSI, so the only variable is the frame and I disagree strongly.
I'd agree it didn't necessarily have anything to do with what the frames were made of but the implication that frame doesn't matter at all I find absurd.

I have been using the same components/wheels with the last 3 carbon frames I have had (an original venge, tarmac sl5 and now sl6) and the difference in how they ride/feel is noticeably different despite all 3 having very similar geometry so the idea that the frame doesn't matter seems pretty silly to me too.

 

[Lombard]

I have been using the same components/wheels with the last 3 carbon frames I have had (an original venge, tarmac sl5 and now sl6) and the difference in how they ride/feel is noticeably different despite all 3 having very similar geometry so the idea that the frame doesn't matter seems pretty silly to me too.

So are you saying that all three of these bikes have exactly the same brand and make of tires, the same size tires inflated to exactly the same pressure?

Tires will make the biggest difference in ride quality. Everything else is comparatively minuscule.

 

[mfdemicco]

I moved everything from one frame to another, kept using the same PSI, so the only variable is the frame and I disagree strongly.
I'd agree it didn't necessarily have anything to do with what the frames were made of but the implication that frame doesn't matter at all I find absurd.

Do both frames have the same geometry? If not, it's not a fair comparison.

By your second paragraph, you are agreeing with me. That is what I was saying.

 

[Jay Strongbow]

Do both frames have the same geometry? If not, it's not a fair comparison.
By your second paragraph, you are agreeing with me. That is what I was saying.

Slightly different but resulting in identical fit. Geometry was close enough to duplicate the fit exactly with one less spacer and about half a cm less set back.

And no, I am not agreeing with this: "That's if you buy that "tuning" really accomplishes anything but market speak. To me, a frame is supposed to be rigid and is a structure to enable the attachment of components in the proper locations."

I would agree with this: "People say that steel rides better, Ti rides better, carbon fiber is too stiff; it's all BS."

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

I know exactly what these terms mean.

Elastic modulus refers to a material’s ability to flex elastically. The upper limit of elastic modulus is yield strength, at which the material flexes plastically (ie it doesn’t return to its original shape). So, bend a bar of metal less than to the point that it would bend permanently, and it’ll flex back.

Metals like Ti and steel typically can flex below this point an unlimited number of times. Aluminum cannot.

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

Boeing, Airbus, etc.? You mean the companies whose latest/greatest plane design incorporate copious amounts of carbon fiber composites???


Sent from my iPad using Tapatalk Pro

Precisely. Did it ever cross your mind that they chose composites because titanium would be too expensive?

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

Young's modulus of Toray T700S (common in road bikes) is 230 Gpa, and garden variety Ti-6AL-4V is around 115 Gpa. Cooked pasta noodle to uncooked respectively.

Tensile strength and modulus of elasticity are not the same thing. They may be related - one may affect the other - but they are not the same characteristic of a material. What’s more, you cannot s

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

Young's modulus of Toray T700S (common in road bikes) is 230 Gpa, and garden variety Ti-6AL-4V is around 115 Gpa. Cooked pasta noodle to uncooked respectively.

Tensile strength and modulus of elasticity are not the same thing. They may be related - one may affect the other - but they are not the same characteristic of a material. What’s more, you cannot simply look at the individual properties of a material in its unbuilt form and extrapolate it into an estimation of the properties of the product it’s being used to build. Steel is a fat “stiffer” metal than aluminum, yet steel frames are known to flex more (because of how they must be built up).

 

[tlg]

Precisely. Did it ever cross your mind that they chose composites because titanium would be too expensive?

lmao. No that is NOT why they chose composites. Give it up! Strength to Weight is a real thing.

The Boeing Dreamliner airframe is nearly half carbon fiber reinforced plastic and other composites. Reducing weight by 20 percent compared to more conventional designs.

Cost of the plane is a small factor. Cost of fuel is significantly larger factor. Airlines would gladly pay more for a plane made from titanium if it was lighter and saved fuel costs over 20 years.

BOEING UPS THE ANTE WITH COMPOSITE-LOADED 787-10 DREAMLINER
So, what is it about the 787-10 that makes the plane so attractive? Drastic improvements in fuel mileage and emissions made possible by a full range of composites that make up entire sections of the plane, including the wings and fuselage.

IT'S ALL ABOUT THE WEIGHT
When the Boeing 747 was first introduced in 1970, it was believed that the company had reached the absolute limit in size and weight.

Engineers have to look at a number of factors when designing a new airplane. First is the total weight of the aircraft, including the aircraft itself along with passengers and cargo. Aerodynamic principles dictate that in order to lift a certain amount of weight off the ground, a plane's wing span has to be commensurate. The more weight you add, the bigger the wings have to be.

COMPOSITE MATERIALS ARE THE ANSWER
So, how did we get from the '70s-era 747 to the modern 787-10? By taking advantage of composite materials. Things like fiber composite panels offer superior strength and rigidity without excess weight. In fact, everything from carbon fiber tubing to fabricated sheets and panels offer the strength and rigidity needed for airframe construction but at a much lower cost in terms of weight.

The 787-10 can seat 330 passengers and fly more than 6,000 nautical miles because of the advantages of composite materials. It is a 224-foot aircraft with a wingspan of just under 200 feet, so every major airport in the world can accommodate it. Its main advantage is fuel savings.

By drastically reducing fuel consumption without sacrificing seating capacity, Boeing has created an aircraft that generates higher revenues per seat. In the ultra-competitive world of commercial airlines, this is everything.

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

there are actually real and very experienced engineers throughout the bicycle industry, many of them w/ doctoral degrees.

Yeah. Sure there are.

I mean, why not? It’s every newly-graduated engineering PhD’s dream to go design bicycles. What could be more enticing than that?

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

Remember Newton's third law? Every action has an equal and opposite reaction? If the frame flexes, it will flex back. Where does the energy go? Not into heat, so into the return flex of the frame.

Ummm....

I’m afraid that you misunderstood Newton’s third law.

The “equal and opposite” force is simultaneous - eg when you push against a wall, the wall simultaneously pushes against you. That’s the idea.

A bike frame flexing and rebounding back is not an example of Newton’s third law.

That being said, work (in Joules) imparted unto the frame to bend it is more than the work. (in Joules) carried out by the frame flexing back. The loss of energy (ie Joules) is to heat.

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

lmao. No that is NOT why they chose composites. Give it up! Strength to Weight is a real thing.

The Boeing Dreamliner airframe is nearly half carbon fiber reinforced plastic and other composites. Reducing weight by 20 percent compared to more conventional designs.

Cost of the plane is a small factor. Cost of fuel is significantly larger factor. Airlines would gladly pay more for a plane made from titanium if it was lighter and saved fuel costs over 20 years.

BOEING UPS THE ANTE WITH COMPOSITE-LOADED 787-10 DREAMLINER
So, what is it about the 787-10 that makes the plane so attractive? Drastic improvements in fuel mileage and emissions made possible by a full range of composites that make up entire sections of the plane, including the wings and fuselage.

IT'S ALL ABOUT THE WEIGHT
When the Boeing 747 was first introduced in 1970, it was believed that the company had reached the absolute limit in size and weight.

Engineers have to look at a number of factors when designing a new airplane. First is the total weight of the aircraft, including the aircraft itself along with passengers and cargo. Aerodynamic principles dictate that in order to lift a certain amount of weight off the ground, a plane's wing span has to be commensurate. The more weight you add, the bigger the wings have to be.

COMPOSITE MATERIALS ARE THE ANSWER
So, how did we get from the '70s-era 747 to the modern 787-10? By taking advantage of composite materials. Things like fiber composite panels offer superior strength and rigidity without excess weight. In fact, everything from carbon fiber tubing to fabricated sheets and panels offer the strength and rigidity needed for airframe construction but at a much lower cost in terms of weight.

The 787-10 can seat 330 passengers and fly more than 6,000 nautical miles because of the advantages of composite materials. It is a 224-foot aircraft with a wingspan of just under 200 feet, so every major airport in the world can accommodate it. Its main advantage is fuel savings.

By drastically reducing fuel consumption without sacrificing seating capacity, Boeing has created an aircraft that generates higher revenues per seat. In the ultra-competitive world of commercial airlines, this is everything.

Dude... did you even read what you quoted? This ar

 

[tlg]

Dude... did you even read what you quoted? This ar

Dude.... yea. Did you?
Do you still not understand why they chose composites over titanium?

 

[Waspinator]

It doesn’t help to use big words when you don’t know what they mean.

lmao. No that is NOT why they chose composites. Give it up! Strength to Weight is a real thing.

The Boeing Dreamliner airframe is nearly half carbon fiber reinforced plastic and other composites. Reducing weight by 20 percent compared to more conventional designs.

Cost of the plane is a small factor. Cost of fuel is significantly larger factor. Airlines would gladly pay more for a plane made from titanium if it was lighter and saved fuel costs over 20 years.

BOEING UPS THE ANTE WITH COMPOSITE-LOADED 787-10 DREAMLINER
So, what is it about the 787-10 that makes the plane so attractive? Drastic improvements in fuel mileage and emissions made possible by a full range of composites that make up entire sections of the plane, including the wings and fuselage.

IT'S ALL ABOUT THE WEIGHT
When the Boeing 747 was first introduced in 1970, it was believed that the company had reached the absolute limit in size and weight.

Engineers have to look at a number of factors when designing a new airplane. First is the total weight of the aircraft, including the aircraft itself along with passengers and cargo. Aerodynamic principles dictate that in order to lift a certain amount of weight off the ground, a plane's wing span has to be commensurate. The more weight you add, the bigger the wings have to be.

COMPOSITE MATERIALS ARE THE ANSWER
So, how did we get from the '70s-era 747 to the modern 787-10? By taking advantage of composite materials. Things like fiber composite panels offer superior strength and rigidity without excess weight. In fact, everything from carbon fiber tubing to fabricated sheets and panels offer the strength and rigidity needed for airframe construction but at a much lower cost in terms of weight.

The 787-10 can seat 330 passengers and fly more than 6,000 nautical miles because of the advantages of composite materials. It is a 224-foot aircraft with a wingspan of just under 200 feet, so every major airport in the world can accommodate it. Its main advantage is fuel savings.

By drastically reducing fuel consumption without sacrificing seating capacity, Boeing has created an aircraft that generates higher revenues per seat. In the ultra-competitive world of commercial airlines, this is everything.

A couple comments in response:

1. First, just because Boeing can take advantage of composite’s benefits doesn’t mean bicycle companies can. Boeing is a large company that hires PhDs galore to study every last aspect of every airplane. Hell, my father had a PhD in mechanical engineering (his thesis was on acoustics) and Boeing hired him to study the acoustics in airplanes. Your average schmo designing bike frames is not playing anywhere even remotely near Boeing’s playing field.

2. Boeing has access to materials and manufacturing techniques and quality control techniques that no bicycle company has, or would be willing to even attempt to acquire.

3. This quote from Boeing doesn’t say anything about cost. Remember the objective of the 787 Dreamliner: the plane was designed to be a plane that would be built in large quantities, traveling to ‘smaller’ destinations as opposed to fewer planes flying to fewer and larger hubs (which is what Airbus bet on when they produced the A380) . Hence, using lower-cost materials was paramount to Boeing and the Dreamliner. That means Ti was out.

 

[tlg]

A couple comments in response:

1. First, just because Boeing can take advantage of composite’s benefits doesn’t mean bicycle companies can.

You seriously don't think bicycle companies aren't taking advantage of composites? :shocked:

3. This quote from Boeing doesn’t say anything about cost. Remember the objective of the 787 Dreamliner: the plane was designed to be a plane that would be built in large quantities, traveling to ‘smaller’ destinations as opposed to fewer planes flying to fewer and larger hubs (which is what Airbus bet on when they produced the A380) . Hence, using lower-cost materials was paramount to Boeing and the Dreamliner. That means Ti was out.

Read it again.
IT'S ALL ABOUT THE WEIGHT
COMPOSITE MATERIALS ARE THE ANSWER

It doesn't say anything about costs because that wasn't the objective. Contrary to what you made up.
"In response to the preferences of airlines around the world, Boeing Commercial Airplanes' new airplane is the Boeing 787 Dreamliner, a super-efficient airplane. The original customer objectives set for the 787 program in 2002 were for a more-efficient airplane that had the seating capacity of a 767 and the range and speed of a 777 or 747."

Yes it's about costs. Fuel costs. Achieved by the superior strength to weight ratio of composts.