My friend Eds 58cm custom 700 grm frame

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Krackor
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by Krackor

Some production frames are over-engineered in some places to ease manufacturing. A frame with modular joints is going to be easier to build than one that is entirely hand-molded, but I bet the latter has a higher potential for stiffness and low weight. I don't know if Ed's frames in particular are better, but it's not as simple as "clean-looking joints equals better frame".

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prendrefeu
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by prendrefeu

What's going on in the upper sequence of that frame manufacturing process?
Can you (Epic-O) or someone explain the tooling underneath the BB/Chainstay assembly? What's being placed in it, and why?
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Ahillock
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by Ahillock

Epic-o wrote:Honestly I would not ride this frame


The frame is made with "continuous fibers running throughout the entire frame, front to rear and all around" so it will look different than a typical frame.

xena
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by xena

Krackor wrote:Some production frames are over-engineered in some places to ease manufacturing. A frame with modular joints is going to be easier to build than one that is entirely hand-molded, but I bet the latter has a higher potential for stiffness and low weight. I don't know if Ed's frames in particular are better, but it's not as simple as "clean-looking joints equals better frame".


Exactly. :thumbup:
Some people on this thread have no idea what they are talking about and the relentless arguing/debate will not prove them right.
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Epic-o
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by Epic-o

xena wrote:
Krackor wrote:Some production frames are over-engineered in some places to ease manufacturing. A frame with modular joints is going to be easier to build than one that is entirely hand-molded, but I bet the latter has a higher potential for stiffness and low weight. I don't know if Ed's frames in particular are better, but it's not as simple as "clean-looking joints equals better frame".


Exactly. :thumbup:
Some people on this thread have no idea what they are talking about and the relentless arguing/debate will not prove them right.


I know it's your friend's frame but you should be a bit more objective and provide better arguments.

Saying that a frame with a tube to tube construction and wrapped joints can be lighter and stiffer than a frame with monocoque joints is going against common sense and what every single manufacturer has been doing during the last few years. With molded joints you have more freedom to shape these important zones and put the material where you want it to be.

Image

Image

I would say that the main reason for Eds' use of honeycomb is to be able to put the material farther away from the neutral axis of the tube and improve stiffness without having to switch to a type of construction with molded joints. Something pretty similar to the use of epoxy molding compound by Guru.

Image

As you can imagine, this is not the most efficient way to use carbon fiber. The material of the inner tube is not placed where it would provide maximum stiffness to the structure. That's the main reason why the best STW ratio frames use monocoque construction for as many tubes as possible (while ensuring good compactation everywhere) and avoid joints between frame elements.

Image

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kgt
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by kgt

nice post Epic-o

prendrefeu wrote:What's going on in the upper sequence of that frame manufacturing process?
Can you (Epic-O) or someone explain the tooling underneath the BB/Chainstay assembly? What's being placed in it, and why?

You mean the epoxy glue?

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prendrefeu
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by prendrefeu

No. I know what epoxy glue looks like.
I asked something very specific to those photos.
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Derf
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by Derf

My thoughts tend to align with Epic-O's/XCProMD here. Hard to argue against fundamentals of mechanics and materials. A light (less material), thin tube (less moment of inertia) doesn't make for stiff. May very well be "stiff enough", and, sure, certain layups are going to squeeze as much out of the material as possible, with deleterious effects on durability. These are all compromises a designer needs to work with but there are no magic bullets here.

Prendrefeu--only guess is it keeps the epoxy cool and easy to mix? Hard to make sense of it.

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53x12
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by 53x12

Derf wrote:A light (less material), thin tube (less moment of inertia) doesn't make for stiff.


Since when are we talking about thin tube? The original discussion was revolving around "kgt" comment that "small diameter tube definitely equals low stiffness." Definitely equals low stiffness is a strong term and pronouncement and not something I would agree with off the bat without taking other factors into the equation.

Big difference between a thin tube + small diameter frame vs. proper tube thickness + small diameter frame. There are plenty of cyclists that like the traditional look of small diameter tubes.



Derf wrote:May very well be "stiff enough", and, sure, certain layups are going to squeeze as much out of the material as possible, with deleterious effects on durability. These are all compromises a designer needs to work with but there are no magic bullets here.



Carbon fiber has significantly better modulus than steel. No reason a small diameter tube frame from carbon fiber could do just as well as a small diameter tube steel frame.

"Stiff enough" is the question at hand and goes back to my comment of how one can judge a frame's stiffness by looking at a picture of it. An honest response would wait for the rider to test ride it themselves or wait for several owners to post reviews on the frame. Each of us are different sizes, weights and type of cyclists looking for different aspects in our frames. What might be too stiff for one, might be perfect for another. Definitely hard to make predictions based off of photos.
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mythical
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by mythical

Jeez, this thread is a clear demonstration of how carbon fiber is better left to actual experts.
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Derf
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by Derf

mythical wrote:Jeez, this thread is a clear demonstration of how carbon fiber is better left to actual experts.


Yeah. I don't think I said anything controversial, given everything I wrote is bog standard Mechanics and Materials stuff that many an ME took as a sophomore in college. Relevant whether a cooked pasta noodle or a boron fiber composite.

xena
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by xena

Lay up type of carbon used can make for a very stiff carbon bike. Materials are getting more advanced and skilled builders like Ed know how to create Bikes that are not only super light but very stiff.
Its that simple.
We are talking about custom made bikes.

Epic- I never said "Saying that a frame with a tube to tube construction and wrapped joints can be lighter and stiffer than a frame with monocoque joints"
Don't put words in my mouth to try and win a debate.

You are only making a generalisation. Super light bikes obviously are not going to be as stiff as a heavy steel bike are they? that's common sense and I never stated that Eds bike was the stiffest bike out there.
That's something you picked up in order to try and slate Eds bikes in the link.
I have seen Eds bikes and I can tell you they are amazingly stiff for such light weights.
You are making a argument that is not there and unless you have rode one of Eds bikes then your comments about Eds bikes are invalid and posting a few photos and making a few assumptions only proves your lack of knowledge and real world experience when it comes to this matter.
Should the 30 grms seat post that I sit on and have been riding for ages [seat post combo Ed made]
Should that hold up. There's no flex and very very comfortable .

You seem to be going on and on to prove a point that does not exist in this context

.
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kgt
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by kgt

53x12 wrote:Big difference between a thin tube + small diameter frame vs. proper tube thickness + small diameter frame.

Thick tubes, even of a small diameter, cannot make a 700gr frame at size 58. One should use thin tubes to reach such a low weight. There is also torsional rigidity where, again, small diameter tubes do not help.

53x12 wrote:"Stiff enough" is the question at hand and goes back to my comment of how one can judge a frame's stiffness by looking at a picture of it.

It's not only about 'looking at a picture'. It is about a frame with small diameter tubes that weights less than 700gr (at size 58). It is common sence that such a frame cannot be stiff. No one has ever done it, not even the biggest guys in the industry. So, unless there is some super advanced technology - which I doubt - a superlight frame with (thick or thin) small diameter tubes tubes will not be stiff enough. Of course there were carbon frames from tvt and look back in the '90s with thin tubes but these were noodles by today's standards.

Anyway it seems that no one has ridden it and no one knows about its technical specifications so we will never know what's the deal...

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by Butcher

prendrefeu wrote:No. I know what epoxy glue looks like.
I asked something very specific to those photos.


I'm not going to even pretend on what I'm going to say is right, but it seems to be epoxy and it is distributed in exact portions. That way a builder will know how much they use. Different size portions to be used for different joints.

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