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#21
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On Wed, 20 Oct 2004 09:28:01 -0500, Tim McNamara
wrote: Look into the Dursley-Pedersen bikes from 100 years ago, built on truss frame principles. Dear Tim, Here's a gallery: http://www.dursley-pedersen.net/model_showhide.html# Carl Fogel |
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#22
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Matt O'Toole Wrote: Tim McNamara wrote: Look into the Dursley-Pedersen bikes from 100 years ago, built on truss frame principles. A standard diamond shaped bike frame is about as perfect a truss as you'll find. Why mess with it? Matt O. The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. Obviously all those holes are not aerodynamic for high speed bikes (although maybe thin mylar sheets overlaid would help this as well as work toward the cleaning issue) and would seem rather expensive to fabricate. -- meb |
#23
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Matt O'Toole Wrote: Tim McNamara wrote: Look into the Dursley-Pedersen bikes from 100 years ago, built on truss frame principles. A standard diamond shaped bike frame is about as perfect a truss as you'll find. Why mess with it? Matt O. The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. Obviously all those holes are not aerodynamic for high speed bikes (although maybe thin mylar sheets overlaid would help this as well as work toward the cleaning issue) and would seem rather expensive to fabricate. -- meb |
#24
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meb wrote:
The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. I think not, otherwise bikes would be built that way already. The standard diamond frame is about as efficient a use of material as there is for that application. Even a carbon monocoque can't top it, or carbon bikes would be built as such. UCI rules don't matter either because if such designs were truly superior, there would be enough of a market among non-UCI gottahaveit types that someone would be building them. Moultons may be intersting, but only as a design exercise. If they were really that good, they and their imitators would be everywhere. After all they've had 40 years to do it. If you have access to some engineering software, you could plug in some hypothetical designs and see for yourself. In this case you're not going to save weight and/or gain strength by downsizing the elements of your truss. Matt O. |
#25
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meb wrote:
The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. I think not, otherwise bikes would be built that way already. The standard diamond frame is about as efficient a use of material as there is for that application. Even a carbon monocoque can't top it, or carbon bikes would be built as such. UCI rules don't matter either because if such designs were truly superior, there would be enough of a market among non-UCI gottahaveit types that someone would be building them. Moultons may be intersting, but only as a design exercise. If they were really that good, they and their imitators would be everywhere. After all they've had 40 years to do it. If you have access to some engineering software, you could plug in some hypothetical designs and see for yourself. In this case you're not going to save weight and/or gain strength by downsizing the elements of your truss. Matt O. |
#26
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In article ,
"Matt O'Toole" wrote: meb wrote: The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. I think not, otherwise bikes would be built that way already. The standard diamond frame is about as efficient a use of material as there is for that application. Even a carbon monocoque can't top it, or carbon bikes would be built as such. UCI rules don't matter either because if such designs were truly superior, there would be enough of a market among non-UCI gottahaveit types that Well, the Trek Y-foil disagrees with you. It was a UCI-legal aero design, but was discontinued after a rule change made it illegal (mandatory seat tubes, dontcha know): http://www.chainreaction.com/Y-Foil.htm#Nomoreyfoils Already, TT bikes are built within an inch of the rules, and pursuit/TT track bikes (with their lesser wind issues on indoor tracks) were built as carbon monocoques until the rules changed for them, too. someone would be building them. Moultons may be intersting, but only as a design exercise. If they were really that good, they and their imitators would be everywhere. After all they've had 40 years to do it. Well, they're still out there, and the small but cultish market for small-wheel bikes carries on. You can still buy high-performance, lightweight small-wheel folders from multiple makers (Dahon, Bike Friday, even Moulton (or at least "AM") if you can afford them). This micro-truss idea may have merit as a better use of materials. If you have access to some engineering software, you could plug in some hypothetical designs and see for yourself. In this case you're not going to save weight and/or gain strength by downsizing the elements of your truss. Matt O. -- Ryan Cousineau, http://www.wiredcola.com Verus de parvis; verus de magnis. |
#27
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In article ,
"Matt O'Toole" wrote: meb wrote: The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. I think not, otherwise bikes would be built that way already. The standard diamond frame is about as efficient a use of material as there is for that application. Even a carbon monocoque can't top it, or carbon bikes would be built as such. UCI rules don't matter either because if such designs were truly superior, there would be enough of a market among non-UCI gottahaveit types that Well, the Trek Y-foil disagrees with you. It was a UCI-legal aero design, but was discontinued after a rule change made it illegal (mandatory seat tubes, dontcha know): http://www.chainreaction.com/Y-Foil.htm#Nomoreyfoils Already, TT bikes are built within an inch of the rules, and pursuit/TT track bikes (with their lesser wind issues on indoor tracks) were built as carbon monocoques until the rules changed for them, too. someone would be building them. Moultons may be intersting, but only as a design exercise. If they were really that good, they and their imitators would be everywhere. After all they've had 40 years to do it. Well, they're still out there, and the small but cultish market for small-wheel bikes carries on. You can still buy high-performance, lightweight small-wheel folders from multiple makers (Dahon, Bike Friday, even Moulton (or at least "AM") if you can afford them). This micro-truss idea may have merit as a better use of materials. If you have access to some engineering software, you could plug in some hypothetical designs and see for yourself. In this case you're not going to save weight and/or gain strength by downsizing the elements of your truss. Matt O. -- Ryan Cousineau, http://www.wiredcola.com Verus de parvis; verus de magnis. |
#28
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Ryan Cousineau wrote:
In article , "Matt O'Toole" wrote: meb wrote: The truss shown on this thread is a truss on the micro level. The traditional diamond frame is a truss on the macroscopic level. The replacing the tubes with a micro level truss would be a further strength to weight enhancement. I think not, otherwise bikes would be built that way already. The standard diamond frame is about as efficient a use of material as there is for that application. Even a carbon monocoque can't top it, or carbon bikes would be built as such. UCI rules don't matter either because if such designs were truly superior, there would be enough of a market among non-UCI gottahaveit types that Well, the Trek Y-foil disagrees with you. It was a UCI-legal aero design, but was discontinued after a rule change made it illegal (mandatory seat tubes, dontcha know): http://www.chainreaction.com/Y-Foil.htm#Nomoreyfoils This whole UCI thing is just plain silly. It's all about preserving tradition and European hegemony. The aerodynamic stuff is mostly BS, but a simple monocoque shape is a simpler, lighter, cheaper way to build a carbon frame, and should be allowed. It lends itself to both one-off garage construction, and cheap mass production. Allegedly the rules are to prevent equipment advantages, or the impression of them. But if frames like this were allowed, everyone could have a 3 LB carbon/thermoplastic Taiwanese frame that's virtually indestructable for a couple hundred bucks. Or maybe *that's* what they're trying to prevent -- the death of the $10k Colnago that "goes soft" in one season. Already, TT bikes are built within an inch of the rules, and pursuit/TT track bikes (with their lesser wind issues on indoor tracks) were built as carbon monocoques until the rules changed for them, too. Notice how they still allow *some* experimentation, because the gear is a big part of the show, even if they don't like to admit it. If they really cared about keeping it a purely athletic endevour, they could just adopt a Keirin-like standard. Moultons may be intersting, but only as a design exercise. If they were really that good, they and their imitators would be everywhere. After all they've had 40 years to do it. Well, they're still out there, and the small but cultish market for small-wheel bikes carries on. You can still buy high-performance, lightweight small-wheel folders from multiple makers (Dahon, Bike Friday, even Moulton (or at least "AM") if you can afford them). This micro-truss idea may have merit as a better use of materials. Look carefully at those small wheel bikes and folders. Except for the Moulton they're even less truss-like than a standard diamond frame. Most of them are cantilever designs, just one, big, fat tube. However, that has more to do with folding requirements than concern for optimum strength/weight. Matt O. |
#29
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On Wed, 20 Oct 2004 07:06:53 -0700, Ryan Cousineau wrote:
In article , unged (Phil Brown) wrote: Only since 1983; the earlier Moultons (from 1962-75) were a single large tube. See http://www.moultoneers.net/ for more detailed history. Ettore Bugatti designed and built a bike with grouped small tubes instead of normal sized tubing in the 20s. None survive but Art Stump built a copy on the 70s. Phil Brown More on the Isotruss: http://www.cyclingnews.com/shows04.p...nterbike/isotr uss It isn't a truss frame in quite the same sense as a Moulton. It's more of a carbon fibre frame with holes in it. But it sure is cool. I haven't seen a quoted weight on the frame, which might be illuminating. Very uh, molecular. I like it. Ron |
#30
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On Wed, 20 Oct 2004 07:06:53 -0700, Ryan Cousineau wrote:
In article , unged (Phil Brown) wrote: Only since 1983; the earlier Moultons (from 1962-75) were a single large tube. See http://www.moultoneers.net/ for more detailed history. Ettore Bugatti designed and built a bike with grouped small tubes instead of normal sized tubing in the 20s. None survive but Art Stump built a copy on the 70s. Phil Brown More on the Isotruss: http://www.cyclingnews.com/shows04.p...nterbike/isotr uss It isn't a truss frame in quite the same sense as a Moulton. It's more of a carbon fibre frame with holes in it. But it sure is cool. I haven't seen a quoted weight on the frame, which might be illuminating. Very uh, molecular. I like it. Ron |
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