Talk:Motorcycle fork

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Contents 1 Motorcycle Fork vs Fork Tube 2 Leading Link and Trailing Link forks 3 Coaxial steering front suspension 4 Naming of fork types 5 Girder Fork vs Springer Fork 6 Merge with fork tubes and triple tree 7 Of handlebars and forks 8 Leading Link and Trailing Link forks 9 Coaxial steering front suspension 10 Naming of fork types 11 Girder Fork vs Springer Fork 12 Merge with fork tubes and triple tree 13 Correct terminology

[edit] Motorcycle Fork vs Fork Tube

It seems that the whole assembly (triple clamp and fork tubes) is called a fork. The BMW, Ducati, and Moto Guzzi web sites all give specifications for the forks on their bikes without mention of "fork tubes".

This also allows for an article to incorporate other fork implementations such as spring forks and BMW's Telelever fork that do not use traditional telescoping fork tubes.

Finally, Dictionary.com lists one definition of "fork" as "the support of the front wheel axles of a bicycle or motorcycle, having the shape of a two-pronged fork." -AndrewDressel 18:29, 8 December 2006 (UTC)

[edit] Leading Link and Trailing Link forks

I don't know who the mysterious M-72 is, but I appreciated and learned form his additions to [this] motorcycle forks page. He should make himself known! -Jeff dean 15:10, 10 December 2006 (UTC)

[edit] Coaxial steering front suspension

I hated quoting as much as I did in the new section, but, without a decent diagram, every time I tried to paraphrase, I couldn't be sure of exactly what a particular term meant. If anyone has a better way to describe this fork, please chime in. -AndrewDressel 17:13, 15 December 2006 (UTC)

[edit] Naming of fork types

Since neither the Telelever or Duolever were invented by BMW, I don't think that they should be title as BMW. Saxon-Motodd invented the telelever type and for many years they were called Saxon-Motodd forks in the British bike press, long before BMW used them. The Duolever was developed by Norman Hossack though used by Claude Fior and John Britten on racebikes long before BMW copied them. Indeed BMW waited until Hossack's patent had expired before copying them. They were frequently referred to as Hossack/Fior forks but it should be noted that Hossack himself described the system as a steered upright.M-72 18:59, 26 December 2006 (UTC)

Excellent info. I've added it. Anyone else using either of these designs these days? Any hope of finding references? -AndrewDressel 20:26, 26 December 2006 (UTC)

The change makes perfect sense. Any chance of putting some references/citation to the inventors? --Cheesy Mike 09:46, 27 December 2006 (UTC)

I'll think about it. I'll release anything under GFDL but it must NOT be Americanised except under GFDL. That is the original British English version is included. I have to admit that I am shocked that no-one has apparently read Foale and reported his studies, even though he is quoted here. While Tony may not be God/Guru, his work is fundamental to appreciating motorcycle suspension. If you want a really weird one to tax your brains, look at the 1931 OEC Duplex steering system - minimal unsprung mass!M-72 13:36, 27 December 2006 (UTC)

It might be better if you didn't. While I would sure like to see that information in the article, I would also hate for it to get tangled up in some kind of editing war. I started (this version of) the article and completely do not care what kind of English it is in (have you seen my spelling?), so long as I can read it, but others clearly do (hence the written policies), and I'm afraid it will just become a mess. Sorry. -AndrewDressel 14:32, 27 December 2006 (UTC)

No worries Andrew, I'd rather provide the information in languages other than English than accept American linguistic Imperialism. US participants seems to totally ignore Wikepedia's guidlines on language and wish to repeat the 2005 RV Wars. They're failing in their geographic Imperialism and will fail in cultural Imperialism. Soon enough one or the other form of Spanish will predominate in the US and it won't matter. M-72 15:27, 27 December 2006 (UTC)

It could be argued, according to the manual of style, that any edits that do use a particular national variation of English establish the language for all future edits of the article. The article only contains one Americanised spelling (hub center steering) and that is a link to a named article. b.t.w. Am I alone in finding the language used in the Coaxial steering section tortuous? "therethrough" and "rotably" are not easily understood, nor am I sure they are real words. It looks like that section is a quote. It would be much better if it were re-written to make it more understandable. --Cheesy Mike 16:17, 27 December 2006 (UTC)

I completely agree about the Coaxial steering section. Sounds like legalese. See the talk section above. -AndrewDressel 17:40, 27 December 2006 (UTC)

[edit] Girder Fork vs Springer Fork

The two descriptions do not do enough of a job, for me anyway, of distinguishing these two types. They both have external springs mounted on or near the triple tree. Anyone have any details that might help? I read on-line that girder forks use a "triangular design"[1] while springer forks are "an early type of leading link fork". Is that correct? I can't tell from the pictures. Does that distinguish them? Inquiring minds would like to know. -AndrewDressel 15:57, 7 February 2007 (UTC)

Springers have two parallel sets of legs. The rear is firmly fixed to the bottom triple clamp (usually brazed or welded). A short leading link holds the wheel and the forward leg which actuates the springs (usually mounted on the triple clamp). The girder on the other hand, fixes the wheel firmly to the (usually a long diamond shape) upright and the pivot points are short links mounted to the top and bottom triple clamps. The spring is (usually) mounted to the girder and compressed against the upper triple clamp. The essential difference is where the pivoting for wheel movement takes place. Clear as mud? M-72 00:58, 8 February 2007 (UTC)

In fact, quit helpful. I'll try to work this into the article. Thanks. -AndrewDressel 02:54, 8 February 2007 (UTC)

[edit] Merge with fork tubes and triple tree

The existing fork tubes and triple tree articles now look like they should be subsections under the telescopic fork section of this article. They are both short enough: triple tree is only a stub. -AndrewDressel 13:56, 14 March 2007 (UTC)

I agree for triple trees. I can't see that ever having enough information to warrant a seperate article.

I'm not so sure about fork tubes. I can see a that there might be written a fairly detailed article discussing, e.g, how telescopic tubes work, the differences between cartridge and non-cartridge forks, more details on upside-down forks (perhaps a history?), differing designs for adjustments, etc. But then again, would that go under "fork tube" or "telescopic forks"? --Pi3832 15:30, 14 March 2007 (UTC)

Perhaps there should be a separate article on telescopic forks that incorporates "fork tubes" and "triple trees"? IIRC, fork tubes are applicable only to telescopic forks, and would therefore fall fully within the scope of an article on telescopic forks. Would that also be true for triple trees? Respectfully, SamBlob 17:58, 14 March 2007 (UTC)

How about this, if or when the telescopic fork section of this article grows to the point of needing its own article, we can break it out then. For now, I think we gain by having all the fork related stuff in one article. Weaknesses in one section and discrepencies between sections will stand out better that way (at least for me). I'm already tempted to copy or even move the fork information from Suspension (motorcycle) and leave just a brief stub. It already points to this as the main article. One descrepency I've already noticed between the two articles is that the old, original fork tube article that I merged into here seems to describe both uppers and lowers as a fork tube. Suspension (motorcycle) seems to use fork tube and fork body for the two pieces. We should straighten that out at least. -AndrewDressel 19:07, 16 March 2007 (UTC)

[edit] Of handlebars and forks

The assertion that the handlebars are "part of the triple clamp" raises several questions:

1. Is the triple clamp part of the fork? It is listed as a subsection under telescopic forks. Is this not correct?

2. Do motorcycles that do not have telescopic forks have triple clamps? If not, where do the handlebars attach? If they do, why is triple clamp a subsection of just telesopic forks?

3. The original edit said that the fork "holds the front wheel and the handlebars". By the new reasoning, isn't it the fork tubes that hold the front wheel? Should the article be edited to reflect that as well?

-AndrewDressel 16:26, 4 April 2007 (UTC)

Okay, let's try this: "A motorcycle fork is the portion of a motorcycle to which the front wheel and the handlebars are connected, usually incorporates the front suspension and front brake, and allows one to steer. In the case of a telescopic fork, it consists of two fork tubes (sometimes also referred to as forks) which hold the front wheel axle and a triple tree which connects the fork tubes and the handlebars, perhaps through a riser, to the frame with a pivot that allows for steering." -AndrewDressel 17:56, 6 April 2007 (UTC)

This also allows for an article to incorporate other fork implementations such as spring forks and BMW's Telelever fork that do not use traditional telescoping fork tubes.

Finally, Dictionary.com lists one definition of "fork" as "the support of the front wheel axles of a bicycle or motorcycle, having the shape of a two-pronged fork." -AndrewDressel 18:29, 8 December 2006 (UTC)

[edit] Leading Link and Trailing Link forks

I don't know who the mysterious M-72 is, but I appreciated and learned form his additions to [this] motorcycle forks page. He should make himself known! -Jeff dean 15:10, 10 December 2006 (UTC)

[edit] Coaxial steering front suspension

I hated quoting as much as I did in the new section, but, without a decent diagram, every time I tried to paraphrase, I couldn't be sure of exactly what a particular term meant. If anyone has a better way to describe this fork, please chime in. -AndrewDressel 17:13, 15 December 2006 (UTC)

[edit] Naming of fork types

Since neither the Telelever or Duolever were invented by BMW, I don't think that they should be title as BMW. Saxon-Motodd invented the telelever type and for many years they were called Saxon-Motodd forks in the British bike press, long before BMW used them. The Duolever was developed by Norman Hossack though used by Claude Fior and John Britten on racebikes long before BMW copied them. Indeed BMW waited until Hossack's patent had expired before copying them. They were frequently referred to as Hossack/Fior forks but it should be noted that Hossack himself described the system as a steered upright.M-72 18:59, 26 December 2006 (UTC)

Excellent info. I've added it. Anyone else using either of these designs these days? Any hope of finding references? -AndrewDressel 20:26, 26 December 2006 (UTC)

The change makes perfect sense. Any chance of putting some references/citation to the inventors? --Cheesy Mike 09:46, 27 December 2006 (UTC)

I'll think about it. I'll release anything under GFDL but it must NOT be Americanised except under GFDL. That is the original British English version is included. I have to admit that I am shocked that no-one has apparently read Foale and reported his studies, even though he is quoted here. While Tony may not be God/Guru, his work is fundamental to appreciating motorcycle suspension. If you want a really weird one to tax your brains, look at the 1931 OEC Duplex steering system - minimal unsprung mass!M-72 13:36, 27 December 2006 (UTC)

It might be better if you didn't. While I would sure like to see that information in the article, I would also hate for it to get tangled up in some kind of editing war. I started (this version of) the article and completely do not care what kind of English it is in (have you seen my spelling?), so long as I can read it, but others clearly do (hence the written policies), and I'm afraid it will just become a mess. Sorry. -AndrewDressel 14:32, 27 December 2006 (UTC)

No worries Andrew, I'd rather provide the information in languages other than English than accept American linguistic Imperialism. US participants seems to totally ignore Wikepedia's guidlines on language and wish to repeat the 2005 RV Wars. They're failing in their geographic Imperialism and will fail in cultural Imperialism. Soon enough one or the other form of Spanish will predominate in the US and it won't matter. M-72 15:27, 27 December 2006 (UTC)

It could be argued, according to the manual of style, that any edits that do use a particular national variation of English establish the language for all future edits of the article. The article only contains one Americanised spelling (hub center steering) and that is a link to a named article. b.t.w. Am I alone in finding the language used in the Coaxial steering section tortuous? "therethrough" and "rotably" are not easily understood, nor am I sure they are real words. It looks like that section is a quote. It would be much better if it were re-written to make it more understandable. --Cheesy Mike 16:17, 27 December 2006 (UTC)

I completely agree about the Coaxial steering section. Sounds like legalese. See the talk section above. -AndrewDressel 17:40, 27 December 2006 (UTC)

[edit] Girder Fork vs Springer Fork

The two descriptions do not do enough of a job, for me anyway, of distinguishing these two types. They both have external springs mounted on or near the triple tree. Anyone have any details that might help? I read on-line that girder forks use a "triangular design"[2] while springer forks are "an early type of leading link fork". Is that correct? I can't tell from the pictures. Does that distinguish them? Inquiring minds would like to know. -AndrewDressel 15:57, 7 February 2007 (UTC)

Springers have two parallel sets of legs. The rear is firmly fixed to the bottom triple clamp (usually brazed or welded). A short leading link holds the wheel and the forward leg which actuates the springs (usually mounted on the triple clamp). The girder on the other hand, fixes the wheel firmly to the (usually a long diamond shape) upright and the pivot points are short links mounted to the top and bottom triple clamps. The spring is (usually) mounted to the girder and compressed against the upper triple clamp. The essential difference is where the pivoting for wheel movement takes place. Clear as mud? M-72 00:58, 8 February 2007 (UTC)

In fact, quit helpful. I'll try to work this into the article. Thanks. -AndrewDressel 02:54, 8 February 2007 (UTC)

[edit] Merge with fork tubes and triple tree

The existing fork tubes and triple tree articles now look like they should be subsections under the telescopic fork section of this article. They are both short enough: triple tree is only a stub. -AndrewDressel 13:56, 14 March 2007 (UTC)

I agree for triple trees. I can't see that ever having enough information to warrant a seperate article.

I'm not so sure about fork tubes. I can see a that there might be written a fairly detailed article discussing, e.g, how telescopic tubes work, the differences between cartridge and non-cartridge forks, more details on upside-down forks (perhaps a history?), differing designs for adjustments, etc. But then again, would that go under "fork tube" or "telescopic forks"? --Pi3832 15:30, 14 March 2007 (UTC)

Perhaps there should be a separate article on telescopic forks that incorporates "fork tubes" and "triple trees"? IIRC, fork tubes are applicable only to telescopic forks, and would therefore fall fully within the scope of an article on telescopic forks. Would that also be true for triple trees? Respectfully, SamBlob 17:58, 14 March 2007 (UTC)

How about this, if or when the telescopic fork section of this article grows to the point of needing its own article, we can break it out then. For now, I think we gain by having all the fork related stuff in one article. Weaknesses in one section and discrepencies between sections will stand out better that way (at least for me). I'm already tempted to copy or even move the fork information from Suspension (motorcycle) and leave just a brief stub. It already points to this as the main article. One descrepency I've already noticed between the two articles is that the old, original fork tube article that I merged into here seems to describe both uppers and lowers as a fork tube. Suspension (motorcycle) seems to use fork tube and fork body for the two pieces. We should straighten that out at least. -AndrewDressel 19:07, 16 March 2007 (UTC)

[edit] Correct terminology

With regard to the photo of USD forks, there is NO slider at the bottom of the fork. There is an axle and brake caliper mount FIRMLY affixed to the fork tube which slides inside the staunchion which is fixed to the triple clamps/triple trees generally by a clamping action. Compare this with the "conventional" telescopic forks where the fork tubes are clamped into the triple clamps and the staunchion/slider (which slides on the fork tube) incorporates the axle and (if any) brake caliper mounts.

The photo of the earles forked BMW is the worst possible photo to show triple clamps as a) it is not a clamping type - the top piece bolts into the fork structure and the bottom piece is welded to the uprights, and b) the "fork tubes" are actually reducing ovals serving as locators for the swingarm.

Much of the terminology grew out of bicycling over a century ago and has been applied and misapplied for so long that we are stuck with it. But that doesn't mean we can't clearly define the technical differences in "fork" types. M-72 02:48, 28 August 2007 (UTC)

If the "fork tube" slides inside the staunchion, then would that tube not be the slider?

Also, by the definition used in the article, a "fork tube" is a completely assembled leg or prong of the fork. Therefore, the "fork tube" consists of the staunchion at the top and the other bit, which I for one would call the "slider", at the bottom. Read the first paragraph of the "fork tube" subsection again, carefully, if you don't believe me. Change it if you have documented proof that it is incorrect.

I noted your objection to the Earles-fork support given as an example of a "triple clamp" and have changed the image to one from a Honda 919. Respectfully, SamBlob 01:43, 30 August 2007 (UTC)

Thank you for the new image. It is better. I disagree that a fork tube is a complete "fork leg", though that may be regional. We are in a complicate area of linguistics and I would like the bicyclists to venture forth as they have shaped our language. Where are you Andrew Dresser?M-72 12:10, 30 August 2007 (UTC)

I too, find the terminology to be a mess. The bicycle world may not be any help. SRAM's website, home of Rockshox, one of the leading bicycle suspension fork brands, uses "uppers" and "lowers" and thus sidesteps the confusion completely. Fox uses "upper tube" and "lower leg". I would love to find a definitive source, but have not yet. I was hoping that you would have something in your library. -AndrewDressel 15:33, 30 August 2007 (UTC)

I was somewhat afraid of that. My search into the bicycle world produced somewhat similar results. My library is extensive but elderly and inconclusive. I believe a call to people such as Tony Foale is in order. He at least could, and I believe would, direct us in a better direction. If no-one objects, I'll ask him to review the matter shortly. M-72 16:56, 30 August 2007 (UTC)

Excellent suggestion. -AndrewDressel 18:52, 30 August 2007 (UTC)