My friend Eds 58cm custom 700 grm frame
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Dad is going to be upset...
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53x12 wrote:kgt wrote:that small diameter tubes in an ultralight frame definitely equals low stiffness.
I'm impressed you can tell the stiffness of a frame by looking at a picture on your screen.
He is not telling the stiffness of a frame by looking at a picture.
It only takes understanding the following concepts:
-elastic modulus
-moment of inertia
-bending moment
-density
to know what he is saying is incontrovertible.
RussellS wrote:VTBike wrote:Totally an ENVE bike. Although then I saw the 3T sticker, and it hit me - It's a 3T bike! But then i looked even closer and saw the Chris King headset.. and i smacked myself. DUH. It's a Chris King bike. You all are so unobservant!!! Credit me for the brilliant deduction please.
Unlike you, I did not use a microscope to examine the bike. I just looked at the picture and saw "ENVE" jumping off the picture. So its obviously made by ENVE. Who else but ENVE would put a huge decal of ENVE on a bike? If this Ed chap made the bike, he would put "Ed" on it to show everyone he made the bike. Since "ENVE" is the only thing on the bike, its obvious ENVE made it. Pretty simple really.
This forum used to be so nice around 2007-2009... Now it's crashing and about to burn.
danbjpa wrote:I liked this Tsubasa Crow. Nice carbon look.
He made your seatpost combo, right?
Enviado do meu iPhone usando Tapatalk
Has made me 2 seat/post combos and a bar /stem combo also ISPed one seat post combo onto my Guru and made crazy light cables guides for both bikes, 4 guides less than a gram We chopped the old ones off and attached the new ones. It dropped about 20 grms off the guru frame and similar for the Trek.
I used quite a heavy [ in WW terms] flat seat for my combos the carbon seat I use [love] weighs 99grms. so the fact that the trek combo came in at 140grms and 129 grms for the Guru shows how skilled Ed is at reducing the weight and keeping the strength.
if I used a AX seat or similar the combos would easy go under 100grms.
Xena a demi god among the digital demimonde that is WW community
http://i.imgur.com/hL5v3ai.jpg
https://www.flickr.com/photos/131970499@N02/
http://i.imgur.com/hL5v3ai.jpg
https://www.flickr.com/photos/131970499@N02/
XCProMD wrote:53x12 wrote:kgt wrote:that small diameter tubes in an ultralight frame definitely equals low stiffness.
I'm impressed you can tell the stiffness of a frame by looking at a picture on your screen.
He is not telling the stiffness of a frame by looking at a picture.
It only takes understanding the following concepts:
-elastic modulus
-moment of inertia
-bending moment
-density
to know what he is saying is incontrovertible.
I have seen some of the carbon Ed uses and some he has developed and I can tell you he has some crazy light carbon that is very stiff.
Think about my seat post -combos and how much the seat weighs 99grms and I am riding around on seat posts that weigh 30 /40 grms that ride great with out issue.
Xena a demi god among the digital demimonde that is WW community
http://i.imgur.com/hL5v3ai.jpg
https://www.flickr.com/photos/131970499@N02/
http://i.imgur.com/hL5v3ai.jpg
https://www.flickr.com/photos/131970499@N02/
XCProMD wrote:53x12 wrote:kgt wrote:that small diameter tubes in an ultralight frame definitely equals low stiffness.
I'm impressed you can tell the stiffness of a frame by looking at a picture on your screen.
He is not telling the stiffness of a frame by looking at a picture.
It only takes understanding the following concepts:
-elastic modulus
-moment of inertia
-bending moment
-density
to know what he is saying is incontrovertible.
Don't bother, that's 53x12...
I would honestly like kevosinn to explain us how such and ultralight frame with skinny tubes is also stiff.
kevosinn wrote:You can engineer a frame with "small" tubes in carbon to be very stiff. You just have to find that nice balance between diameter and wall thickness IMO. Thats what I have really been working on.
Is it the honeycomb? Some reinforcements? Some 'secret' carbon formula? Magic? Something else? How is he capable of designing something that even the biggest manufacturers cannot achieve?
Maybe his answer is "my frame is not too stiff but I don't think too much stiffness is a good thing".
kevosinn wrote:Its true that a larger diameter tube is much stiffer but at what point does it become too stiff?
I would totally accept that, I would even agree.
xena wrote:danbjpa wrote:I liked this Tsubasa Crow. Nice carbon look.
He made your seatpost combo, right?
Enviado do meu iPhone usando Tapatalk
Has made me 2 seat/post combos and a bar /stem combo also ISPed one seat post combo onto my Guru and made crazy light cables guides for both bikes, 4 guides less than a gram We chopped the old ones off and attached the new ones. It dropped about 20 grms off the guru frame and similar for the Trek.
I used quite a heavy [ in WW terms] flat seat for my combos the carbon seat I use [love] weighs 99grms. so the fact that the trek combo came in at 140grms and 129 grms for the Guru shows how skilled Ed is at reducing the weight and keeping the strength.
if I used a AX seat or similar the combos would easy go under 100grms.
Do you have a link to your current bike? I'm interested to see the Guru...
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How are we quantifying the "stiffness" of these frames? My R5ca I would not label a stiff frame, I reserve that for a Tarmac and above in the stiffness category. That doesn't mean it can't be the best frame I've ever ridden but I keep seeing threads about X builder making a light frame and it's proclaimed to be stiff, how did you come to that conclusion?
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XCProMD wrote:53x12 wrote:kgt wrote:that small diameter tubes in an ultralight frame definitely equals low stiffness.
I'm impressed you can tell the stiffness of a frame by looking at a picture on your screen.
He is not telling the stiffness of a frame by looking at a picture.
It only takes understanding the following concepts:
-elastic modulus
-moment of inertia
-bending moment
-density
to know what he is saying is incontrovertible.
The comment: "that small diameter tubes in an ultralight frame definitely equals low stiffness" is definitely BS. Especially without knowing layup protocol, carbon fiber used or the binding polymer. That claim is false and is not true. Not to mention, what the hell does "low stiffness" mean? Low stiffness compared to what? Compared to some monocoque carbon fiber frame that rides like a rock?
To say and then to believe the statement that "that small diameter tubes in an ultralight frame definitely equals low stiffness" is idiotic and just not even true.
Ok, so whenever we use a physical term we absolutely need to specify either:
-a measurable amount in standard units
-or a benchmark to compare to.
Perfect, I'll remember to do that in this forum in the future. In my job we are allowed to express in the same terms as Kgt did, even when discussing with customers. If I tell a crane manufacturer "that cross section in a light boom definitely equals low stiffness", and similar expressions are usual in our meetings, they understand what I mean and they understand why. Same thing with the automotive or aerospace customers. I see it doesn't work here.
I don't know of any "lay up protocol" (you are misusing the term, very likely because you learned it on the Internet, but I have no time to rescue from your mistake), carbon fibre or binding polymer that can counteract the effect of the moment of inertia in a CFRP hollow section. If you do you are sitting in a pile of cash that will make you rich for the rest of you life.
20 years designing metal and composite moving structures and still I'm curious and humble enough to learn everyday. I wait for your contribution.
-a measurable amount in standard units
-or a benchmark to compare to.
Perfect, I'll remember to do that in this forum in the future. In my job we are allowed to express in the same terms as Kgt did, even when discussing with customers. If I tell a crane manufacturer "that cross section in a light boom definitely equals low stiffness", and similar expressions are usual in our meetings, they understand what I mean and they understand why. Same thing with the automotive or aerospace customers. I see it doesn't work here.
I don't know of any "lay up protocol" (you are misusing the term, very likely because you learned it on the Internet, but I have no time to rescue from your mistake), carbon fibre or binding polymer that can counteract the effect of the moment of inertia in a CFRP hollow section. If you do you are sitting in a pile of cash that will make you rich for the rest of you life.
20 years designing metal and composite moving structures and still I'm curious and humble enough to learn everyday. I wait for your contribution.
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XCProMD wrote:Ok, so whenever we use a physical term we absolutely need to specify either:
-a measurable amount in standard units
-or a benchmark to compare to.
Perfect, I'll remember to do that in this forum in the future. In my job we are allowed to express in the same terms as Kgt did, even when discussing with customers. If I tell a crane manufacturer "that cross section in a light boom definitely equals low stiffness", and similar expressions are usual in our meetings, they understand what I mean and they understand why. Same thing with the automotive or aerospace customers. I see it doesn't work here.
I don't know of any "lay up protocol" (you are misusing the term, very likely because you learned it on the Internet, but I have no time to rescue from your mistake), carbon fibre or binding polymer that can counteract the effect of the moment of inertia in a CFRP hollow section. If you do you are sitting in a pile of cash that will make you rich for the rest of you life.
20 years designing metal and composite moving structures and still I'm curious and humble enough to learn everyday. I wait for your contribution.
If you are telling a crane manufacturer "that cross section in a light boom definitely equals low stiffness" are you not saying the stiffness is not enough and is a safety concern? So what does low stiffness mean? Does it mean "low stiffness" as in it is less stiff than a super stiff frame like a Velocity Magnus. Or does "low stiffness" mean that there isn't enough stiffness and is it close to zero and a safety concern?
If it is the first, less stiff than a super stiff frame (Velocity Magnus), who cares if it has enough stiffness for the rider and use.
If it is the later, basically zero stiffness, then how can one make that analysis on a computer screen without testing or using the frame in question.
I assume with your super fancy crane, that you do some testing before you say the "light boom definitely equals low stiffness."
Protocol meaning procedure. You need to get out more and do more reading if you haven't heard of that term before. Call it carbon fiber lay up schedule if you want.
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XCProMD wrote:20 years designing metal and composite moving structures and still I'm curious and humble enough to learn everyday. I wait for your contribution.
Since you haven't heard of carbon fiber "layup protocol" after 20 years in the industry, maybe you need to do some more reading?
http://cordis.europa.eu/result/rcn/164412_en.html
https://www.researchgate.net/publicatio ... ter_fibres
http://www.jamisbikes.com.ph/philippine ... hsldi2.pdf
http://www.sciencedirect.com/science/ar ... 5X13001152
Last edited by tranzformer on Sun Mar 06, 2016 6:04 pm, edited 1 time in total.
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All this fuss for a frame ENVE obviously made?
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