Talk:Bicycle frame

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This article is written in American English, which has its own spelling conventions (color, defense, traveled) and some terms that are used in it may be different or absent from other varieties of English. According to the relevant style guide, this should not be changed without broad consensus.

A fact from Bicycle frame appeared on Wikipedia's Main Page in the Did you know column on 29 October 2004. The text of the entry was as follows:

Did you know... that modern bicycle frame construction is usually founded on a diamond-frame design?

A record of the entry may be seen at Wikipedia:Recent additions/2004/October.

Wikipedia

Aluminum vs Steel debate

I've removed some inaccurate references to this ongoing bicycle techie arguement from the Steel section. There are a lot of subtle references to this debate in the steel section (I've removed it) it said that steel was old fashioned, heavy and cheap. There is some of this in the Aluminum section where is talks about Aluminum being "generally agreed" to be heavier. There is also a lot of emphasis on Aluminum fatigue which is probably from people taking a pro-steel perspective. And all the stuff about frame flex doesn't look NPOV. Anyway, perhaps we should have something that objectively describes that there is debate about the benefits of each material... Though this would have to be done at the same time as removing the excessive sideways references to the debate that are all over the place elsewhere in the article. Also it's really only a Sports biking argument as the vast majority of utility and commuting bike are steel, all other materials are unusual with some pluses and minuses to them.

Frankly, after cleaning all that up, I'd like to see more in depth steel discussion of the types of steel and properties. I've added mention of 4130 steel which is very common, at least on the bikes here in Canada.

Perhaps we should make this article more managable by ***MAJOR PROPOSAL*** cleaving off the materials discussion into it's own seperate bike frame materials section? I actually stumbled upon (and then got caught up editing) this article trying to find a nice list of various types of tubing in both steel and aluminum bicycles. I'm trying to research tubes. But really this information isn't here at all but a materials article could include it, have space for encompassing material debates, and not bog down the whole notion of what a frame is in the main article. Rusl (talk) 05:02, 23 September 2008 (UTC)[reply]

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)[reply]

Tone of Aluminum section

The forth paragraph of aluminum section needs work. Although I largely agree with the opinion of the author regarding the aerodynamic effect verses structural compromise of non-round tubing, the "beware" statements are not appropriate for wikipedia. I think this statement of such a controversial nature certainly needs a source if anyone can think of one. Bdentremont (talk) 05:34, 28 July 2008 (UTC)[reply]

I have placed a "inappropriate tone" template on it.

Frankly, I believe that the entire section on the weakness and failure properties of radically hydroformed Aluminum tubing are completely bullshit and have absolutely zero technical basis - you don't have to look very far or delve heavily into the engineering analysis (which has obviously not been done by the author of this section) to find race winning, acclaimed framesets that use said types of tubing. Many of them also have varying thickness profiles in the tube cross section to mitigate any losses in cross sectional strength. Panzerjager88 (talk)

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)[reply]

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

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)

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)[reply]

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)

from seat stay

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.

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)

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)[reply]

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)[reply]

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[reply]

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)[reply]

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[reply]

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)[reply]

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)[reply]

The vandalism was in the transcluded template: Template:TOCleft. Severo^TC 10:11, 14 November 2007 (UTC)[reply]

Phew! Glad you found it and got rid of it. -AndrewDressel 14:52, 14 November 2007 (UTC)[reply]

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)[reply]

Seems like a good idea :) Severo^TC 23:30, 18 February 2008 (UTC)[reply]

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)[reply]

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)[reply]

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)[reply]

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)[reply]

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)[reply]

humbert

The {{for| template at the top of this article mentions Humber (bicycle). The article referred to is short, but seems to refer to a bicycle manufacturer who made a number of novel frame types, but not a frame type in itself. Could someone clarify this?--Keithonearth (talk) 06:50, 1 October 2008 (UTC)[reply]

That is true. Articles about the frame types would be ideal, but the Humber bicycle article makes the only mention of those frame types that I know of. If we remove the Humber bicycle article from the bicycle frame article, I think the information about other frame times will be essentially lost. -AndrewDressel (talk) 11:23, 1 October 2008 (UTC)[reply]

That's a good point, I'd say your right and the humbert link should stay, but could we make it more clear?

But maybe it's getting too wordy.--Keithonearth (talk) 18:28, 1 October 2008 (UTC)[reply]

Claims in "Carbon Fibre" section

"The ability to design an individual composite tube with properties that vary by orientation cannot be accomplished with any metal frame construction commonly in production."

This is false; any tube that does not have rotational symmetry (e.g. one with a rectangular cross section) has properties that vary by orientation. If the statement were qualified to say "a symmetrical" instead of "an individual", this would be rectified. However, the sentence would still read "The ability to design [...] a composite tube [...] cannot be accomplished with any metal frame construction." —Preceding unsigned comment added by PaulKishimoto (talk • contribs) 06:12, 21 October 2008 (UTC)[reply]

Steel Generally Used

I added a request for a reference to the claim that 'generally frame tubes are made of steel'. My experience working at a bicycle shop in Tucson, AZ is that most new bikes are being made of Aluminum. I would say that this is true both of bicycle shop brands and department store brands. I believe the statement to not reflect the current trends of the last 5 years. Historically I don't argue that bicycle were made of steel but I don't think that this is the current trend. Please add a reference to back this up or remove it. Ender8282 (talk) 20:25, 12 February 2009 (UTC)[reply]

While I agree with you for the most part, I do think this is another example of how difficult it is to make global statements on how one bike thing is more common than another. Surely Chinese and Indian roadsters are some of the most common bikes globally? They're made from "gas pipe" steel, lugged. How about saying that steel and alu are the most common frame materials?--Keithonearth (talk) 06:55, 13 February 2009 (UTC)[reply]

What is this article about?

A resent change to the opening blurb of this article has specified that the article is only about Diamond frames. This seems unnecessary to me, and even undesirable. I would suggest that we should have an article that is an overview of bicycle frames in general, and that we shouldn't exclude other frame types from this article. I'd also say that it is appropriate for an article giving an overview of bicycle frames in general, to mainly talk about the most common one: the diamond frame. The second most common one, the step-through frame shares many characteristics with the diamond frame, and all the tubes have the same name, construction technique and materials are virtually identical. Of the 3 links provided in the header: step-through frame, recumbent bicycle and Humber (bicycle), Step-through is nominally about a bicycle frame, but in fact discusses the type of bicycle in general. The other two articles are not about bicycle frames at all: the recumbent article talks about a wide range of characteristics about this style of bicycle, but on skimming through did not have any info about the frame construction, materials, or anything else. The Humbler article is about an obscure and obsolete bicycle manufacturer that at one time made a non-standard frame. It has little info. I propose changing the header to "This article describes bicycle frames in general with emphasis on diamond frames. For more non-diamond frames see step-through frame, recumbent bicycle and Humber (bicycle)."--Keithonearth (talk) 06:52, 9 April 2009 (UTC)[reply]

I like your suggestion. -AndrewDressel (talk) 13:43, 9 April 2009 (UTC)[reply]

Ok, I've done it, with the minor modification that I said ...with emphasis on diamond and step-through frames. I did this because there is so much overlap between the two. If anyone feels this is inappropriate and thinks my first suggestion is better, feel free to edit it.--Keithonearth (talk) 18:54, 10 April 2009 (UTC)[reply]

Track bike bottom bracket height

I've copied this here from the Track bike article in hopes of finding an answer. -AndrewDressel (talk) 13:41, 2 May 2009 (UTC)[reply]

"higher bottom bracket for additional cornering clearance." I've often heard this, but have never heard how much higher.

All I can find in UCI regulations (http://www.uci.ch/imgArchive/Rules/1gene-E.pdf) is:

Technical specifications

Except where stated to the contrary, the following technical specifications shall apply to bicycles used in road, track and cyclo-cross racing.

1.3.015 The distance between the bottom bracket spindle and the ground shall be between 24 cm minimum and maximum 30 cm.

Cannondale (http://www.cannondale.com/bikes/03/geo-40.html) lists the bottom bracket height for their track bike is 28.2 cm.

Fuji (http://www.fujibikes.com/geometry.asp?bike_id=17) lists the bottom bracket height for their track bike is 29.2 cm.

Others, such as Bianchi and Surly, just say "track legal". What does that mean exactly?

I get the general "heigher for pedal clearance with a fixed gear", but it would seem also to depend on crank arm length. Does anyone know what the real requirement is? How would a particular bicycle at a track event be found to be legal or illegal?-AndrewDressel 00:03, 20 October 2007 (UTC)[reply]

Crank arm length affects the leverage on the gear. So if you have a long crank arm, it has to be mounted high enough to clear corners. I belive there is a mathematical formula but I do not know it. I personally use 65 size crank arms and a bottom bracket that messures 11 and 3/4" from the ground to center of allen bolt attaching crank arms. —Preceding unsigned comment added by Mrmike23 (talk • contribs) 18:12, 9 December 2007 (UTC)[reply]

We sure would like to see that formula. Anybody? -AndrewDressel (talk) 13:29, 2 May 2009 (UTC)[reply]

I'm confused by the reasoning here. Surely a track bike will lean less relative to the surface on which it is riding; the whole point in a banked track is to stay more perpendicular to a leaning bicycle than a flat surface? 86.0.203.120 (talk) 15:27, 24 August 2008 (UTC)[reply]

That a track bike leans less on a banked track is only true when the bike is following a line concentric (I suspect that is not the correct word, but I don't think parallel is correct either, and I can't find a better alternative) to the track. During turns to avoid another cyclist, or when the bike leans from side to side during a sprint, the bank of the track is not a factor, and it is important that the pedals, which are of course forced to rotate by the forward motion of the bike, not strike the track surface. The questions remains: "What exactly does 'track legal' mean?" -AndrewDressel (talk) 17:32, 25 August 2008 (UTC)[reply]