Talk:Bicycle frame

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Contents

[edit] Image added to frame size section

I added the diagram of common bicycle measurements because these are terms that abound bikeswaps and ebay's bikes for sale, etc. I hope that this is not seen as redundant as the other diagram addresses actual parts and this one addresses accurate measurements. --Circlemaker 06:16, 04 July 2006 (UTC)


[edit] Minor edit of Aluminum section

I added the bit about alloying extends the fatigue life to many years. The original text made it sound like aluminum frames will just break on you. While this may happen, it usually takes quite a few years of intense riding. I still see Cannondale CAAD 3 frames on the road. Comatose51 02:45, 29 August 2005 (UTC)

Should bicycle frame construction be merged into this? --Christopherlin 02:48, 13 Nov 2004 (UTC)

[edit] Merged in material from bicycle frame construction

Whew. That took a while.

Could anybody add in material about geometries (road vs. comfort vs. hybrid vs. mountain) or any historical information? --Christopherlin 06:24, 17 Nov 2004 (UTC)

[edit] Triangle vs. trapezoid

195.179.206.165 notes that the front/main "triangle" is technically not one, as the top and down tubes don't intersect. However, most references I've seen call it the triangle nonetheless. Thoughts? --Christopherlin 03:38, 24 Feb 2005 (UTC)

Triangle. --Kit transue 21:01, 10 Apr 2005 (UTC)
Triangle as well, if one is to go on what The UCI has to say, in rule 1.3.020, "the frame of the bicycle shall be of a traditional pattern, i.e. built around a main triangle." even though their later definition of the main triangle clearly leaves room from forming of a trapezoid. see http://www.uci.ch/imgArchive/Rules/1gene-E.pdf --Chinakow 05:51, 21 April 2006 (UTC)

[edit] frames vs. geometries?

Suggest the geometry discussion be moved more to the cycle types category, and it be made more clear that the various frame components talked about here (or scheduled to be moved into this article) are based on the tubing-constructed safety bicycle.

I guess it seems that the article presumes the only frame is a safety frame, despite efforts to make it more inclusive. --Kit transue 20:05, 25 Mar 2005 (UTC)

I'm all for being more inclusive. Feel free to add mentions of less common frame types. The safety bicycle is the predominant one today, of course, so it does get the most mention.
I noticed that you made an article for Mixtie, which is but briefly covered in the main article here. The main article size isn't too big right now. I think that things about geometry should stay here. Duplication/expansion within each cycle type article would be good.
The reason I put merge notices on the various tubes is because of the short length of those articles, with little room for expansion as individual articles. Going to clarify the focus of the article, similar to the end of the first paragraph of mountain biking in a sec. --Christopherlin 21:23, 25 Mar 2005 (UTC)
The tube argument makes lots of sense. Still in favor of putting detailed descriptions of the different frame types in the cycle types category; the mixtie is an example of why I think it's wise to have those elsewhere. The mixtie isn't described here at all--yeah, it's got a lower standover height, but it achieves it in a way that puts less stress on the seat tube than the open frame described here. I find those details interesting, but fear putting all them in would detract from the readability of this article. --Kit transue 21:01, 10 Apr 2005 (UTC)

What do folks think about detailing the effects the geometry variables have on the performance/utility of the bike? Something like:

Bottom bracket height: determines clearance of pedals and center of gravity. High BB height for fixed gears and mountain bikes, lower BB for touring, road, etc.

Standover height: the distance between the top tube and ground. Lower for moutain bikes where you might need to step on uneven terrain, lower still for convenience mounting the bicycle (clothing, touring). Higher moves the frame elements further apart to make the frame stiffer.

Head tube angle: steep for livelier steering, shallow for self-centering. (surely there's something about camber somewhere.)

Wheelbase: long for touring to keep racks out of the way, move the CG forward, allow for more water bottles :-) Long to reduce pitching over uneven surfaces. Short to increase responsiveness.

Suspension: heavier multi-link for controlling bob, lighter single pivot for long travel, simplicity, and weight, none for....

and so on, covering riding position and the like.

That would lay the groundwork for better understanding the cycle types.... --Kit transue 21:01, 10 Apr 2005 (UTC)

[edit] from seat stay

Upper portion of a road bicycle dual seat stay made from carbon fiber, bonded onto an aluminum main triangle.
Upper portion of a road bicycle dual seat stay made from carbon fiber, bonded onto an aluminum main triangle.

A Single seat stay refers to seat stays which merge onto one section before joining the front triangle of the bicycle, thus meeting at a single point. A dual seat stay refers to seat stays which meet the front triangle of the bicycle at two separate points, usually side-by-side.

[edit] Frame geometry specification

In addition to saddle height, reach, etc., what about bottom bracket height and wheelbase? I don't know if the latter is spec'd as axle-to-axle, tire contact-to-contact, or bottom bracket-to-axle. Perhaps someone more knowledgeable could fill in here if these are useful? --Kit transue 21:01, 10 Apr 2005 (UTC)


[edit] Focus on racing bicycles

I have some issues with the pictures used on this article. It seems to me that judging just by the photographs, road/racing bicycles are over-represented. Maybe use more Utiliy or MTB type bike photographs more, since the former vastly outnumber racing/road bikes, anywhere in the world except perhaps in North America. —The preceding unsigned comment was added by Chicbicyclist (talk • contribs) .

Yeah, all the other types of bicycles and cycling are underrepresented. Perhaps you'd like to help out with what you know. --Christopherlin 02:58, 20 April 2006 (UTC)

[edit] Carbon fiber as "primary" non-metalic material

While I was unable to find a source that explicitely lists carbon fiber as the primary non-metallic material, I have listed three sources, including a page from the highly-regarded and often cited Sheldon Brown's web site, that compare frame materials. All three include carbon fiber as the only non-metallic material in their discussions. Another way to look it this would be to list all the major manufacturers that offer carbon fiber frames (Trek, Specialized, Giant, Orbea, Felt, Raleigh, Scwhinn, Look, Seven, even aluminum frame pioneer Cannondale) vs all the major manufacturers that offer frames of any other non-metallic material. If there are any sources that indicate that any other non-metallic material is commonly used, or even currently in production (other than beautifully hand-crafted wood and bamboo), I would love to see it. -AndrewDressel 14:46, 13 March 2007 (UTC)

Hello Andrew, I have taken a look at the most recent references you added to the article bicycle. The are excellent references for much of the material. Unfortunatelly, I coudn't find, out of the 3 links, anything that mentions "carbon fiber" is the most popular non-metalic frame. Of course it is an "increasingly popular frame material"[1]. I will change the word "primary" to "popular." Perhaps, you could also place your references at various appropriate locations throughout the paragraph since having them all at the begining doesn't seem as relevant. Thank you! --CyclePat 17:11, 13 March 2007 (UTC) Copied from User talk:AndrewDressel
Seems silly, but okay. There isn't a source verifying that the frame is the main component of a bicycle. There isn't a source confirming that the most common frame design is based on the safety bicycle. There isn't a source specifying that the rear brake cable is most commonly routed along mounts on the top tube. There isn't a source corroborating the claim that a more economical method of bicycle frame construction uses cylindrical steel tubing connected by TIG welding. Why you let these slide while questioning the preponderance of evidence supporting the claim that carbon fiber is the primary and most commonly used non-metallic frame material is beyond my understanding. Does this somehow strike you as original research? Do you have support for a counter claim? -AndrewDressel 17:29, 13 March 2007 (UTC)
Please take note that there is strict policy regarding inclusion of material. Wikipedia articles must be based on reliable sources. Instead of trying to find counter exemples to this rule you may wish to try improve the sections of the article which you highlighted as lacking proper citations. --CyclePat 06:02, 15 March 2007 (UTC) Copied from User talk:AndrewDressel
If there is some question about the reliability of the sources I cite, please tell me what it is. I believe there is no point in looking for citations for the examples I highlighted because the points are widely agreed upon and there is not likely to be any source that bothers confirming them. That is why I chose those examples. The same is true of the primacy of carbon fiber among non-metallic frame materials. Due to your objections, I'll leave this discussion here and let readers draw their own conclusions. -AndrewDressel 14:48, 15 March 2007 (UTC)

[edit] Weird image that appears to be some sort of vandalism

Does anyone else see "Image:Foreskin penis cr07.jpg" at the top of the article page? The image does not exist, so it doesn't show, but a transparaent box covers the first paragraph of the article. I can find no trace of it when I edit the page nor in the history. It does not appear in a preview of the page and it does not appear in my view of any previous version, just in the current version of the article. -AndrewDressel 19:26, 7 November 2007 (UTC)

The vandalism was in the transcluded template: Template:TOCleft. SeveroTC 10:11, 14 November 2007 (UTC)
Phew! Glad you found it and got rid of it. -AndrewDressel 14:52, 14 November 2007 (UTC)

[edit] Reorganization

Any objections to moving most of the frame geometry section to the existing Bicycle and motorcycle geometry article? That would enable a more-comprehensive discussion of the topic in one place. This article is already 31k long, and moving some material out would help bring it back down to size. -AndrewDressel (talk) 23:24, 18 February 2008 (UTC)

Seems like a good idea :) SeveroTC 23:30, 18 February 2008 (UTC)

[edit] Fatigue

The current article states that "in contrast to some steel and titanium alloys, which have unlimited fatigue life, aluminum has no endurance limit" What is meant by this? The fatigue life of aluminum is *much* shorter than that of ti or steel. But Neither ti nor steel have an unlimited fatigue life. Aluminum, while not having an 'endurance life', as long as steel or ti certainly has an endurance life. I have bikes that have seen millions of load cycles and are still in one piece. Ender8282 (talk) 20:32, 3 April 2008 (UTC)

The endurance limit is the maximum cyclical stress that can be repeatedly applied without fatigue ever occuring. Aluminum doesn't have such a limit (a stress limit not a lifetime limit) so any repeated stress, no matter how small will eventually lead to failure. I've taken out this term because it's probably misleading as you say.Kallog (talk) 09:34, 4 April 2008 (UTC)

I see you took out the mention of unlimited fatigue life. It's true we can't know that it really is infinite, but this is how it's usually described. It's distinctly different from the finite-but-long life of alloys without an endurance limit. See here Bicycle frames may not be designed for unlimited fatigue life, but steel parts typically are so it seems safe to generalize to bicycle frames. Kallog (talk) 04:05, 28 April 2008 (UTC)

Before trying to address the issue here, I've spent some time trying to clean up the Fatigue (material) and Fatigue limit articles. It appears, from the authors I've cited and ASTM International that fatigue life is only defined in terms of a specified stress. Without specifying the stress, fatigue life is meaningless. In that case, either fatigue limit or endurance limit are the terms that should be used here to distinguish between the nature of steel and aluminum. Steel has a clearly defined stress limit below which prevailing current practice assumes that fatigue failure will never occur. Aluminum does not. I found no mention, in any of the textbooks I examined, of the new research that suggests that this limit does not actually occur even in steel. That doesn't mean I contest the new research, but suggests that this article on bicycle frames need not take it into account.-AndrewDressel (talk) 18:48, 28 April 2008 (UTC)
Looks good, you've managed to avoid having to say how it applies to bicycles, which we probably don't know. Kallog (talk) 00:08, 29 April 2008 (UTC)