Talk:Motorcycle fork

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)

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)

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)

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)

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" 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)

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)

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)

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)

Undead link?
Dead or alive?

The above link is listed as being dead by User:BlevintronBot, and, when I click the link in the references section of the article, I get a 404 error. I found an archive page and added it, but the archive page has no diagrams.

Armed with the title and the author name, I searched in Google for "Telelever Telescopic Cossalter" and got the link with which I started this section. There was the article, diagrams and all! I decided to change the old URL for this one, but I figured I would find the archive for this new site to start with.

The archives for the "new" URL looked quite familiar, and I realized that this site, showing properly with all diagrams, is the same site that gave, and still gives, a 404 error when trying to access it from the article!

How does one proceed with this undead site? Is there any way to make the site show up in the citation template?

Sincerely, SamBlob (talk) 08:00, 7 April 2012 (UTC)


 * is live
 * is dead


 * They just took down the URL with "DINAMOTO" and replaced it with "dinamoto". But if you do have a truly dead page that has a Wayback archive you can use, you keep the old one in  and put the new one in   and add , and remove the dead link tag, like this:




 * So it displays like this:




 * --Dennis Bratland (talk) 15:18, 7 April 2012 (UTC)


 * Thank you. I've changed the link to the live one and it works.  The Wayback Machine doesn't seem to be case-sensetive, though. Sincerely, SamBlob (talk) 20:17, 7 April 2012 (UTC)

Steering needs no handlebar
"(The fork) allows the bike to be steered via handlebars" this sentence is - so simply - true only for three(or more)-wheeled (motor-)cycles. Two wheelers of usual geometry (tandem position of (narrow) wheels, only front wheel axle may turn around an non -vertical, but backward tilted axis fixed in the frame that holds the back wheel) are - above a pretty low minimal speed - steered in a more complicated way. There is no need for a handlebar. As children know.

But a handlebar helps to hold the equilibrium at the start the ride, as well at the end, to damp the movement of the fork rolling over coarse gravel, to sit comfortably, to actuate motor, brake, clutch, ... and to make a handstand during riding ;) --Helium4 (talk) 12:08, 15 February 2014 (UTC)


 * The relative roles of various steering inputs is already extensively addressed, along with many reliable sources in the countersteering and bicycle and motorcycle dynamics articles, but yes, torque from the handlebars is not the only possible steering input. I've adjusted the wording to allow for other options. -AndrewDressel (talk) 13:49, 15 February 2014 (UTC)


 * This is a common misconception, and should probably be added to List of common misconceptions. See The No BS Machine for proof that body-steering a motorcycle is not possible. There are some special cases, but in general, it holds. --Dennis Bratland (talk) 15:35, 15 February 2014 (UTC)

US or UK English?
I notice another article quietly flipping from UK English to US. What happened to WP:ENGVAR? Castor angle isn't incorrect, it's a UK spelling. Andy Dingley (talk) 11:15, 30 April 2014 (UTC)


 * The trick for this article is divining what the original variety of English might have been. The edit history indicates that the first text appeared in my 9 December 2006‎ edit, but my edit summary says "Restore article and add mention of variations". At this point, I can't remember where I might have been restoring text from, and more importantly, if "castor" implies a variety of English or is simply a typographical error. Without some clear indication such as "tyre", "colour", "fibre", or "behaviour", I doubt we can ever know for sure. -AndrewDressel (talk) 12:16, 30 April 2014 (UTC)
 * Or castor. I'm tired of seeing "Might be confused with castor oil" or "Unrelated Pollux" being used as an excuse to remove valid UK spellings. Andy Dingley (talk) 12:32, 30 April 2014 (UTC)
 * Much less so, I believe, because castor is also a common misspelling of caster in the US, likely due in part to the fact that spell checkers don't flag it, unlike the other examples I listed above. Yes, I also found the edit summary gratuitously rude. -AndrewDressel (talk) 14:27, 30 April 2014 (UTC)

Girder Forks section - contains incorrect use of telescopic fork terminology
This section was added by a long-gone editor (2008) in January 2007, starting here, then expanded by a current-editor who again repeated the terminology. It wrongly IMO makes repeated use of the terms "triple clamp" and "top and bottom triple clamps" when there are no such clamps on girder forks. I've sat on this for two years waiting (hoping) that an American editor would notice and be able to over-write with the correct term(s). I've accessed a 1964 Vincent fork strip and refurbishment article in the house, but the terms used may be Vincent-specific and not generic-enough (or American-enough) for me to confidently over-write it. The article also has wikilinks to Triple tree (a redirect) which circles to nothing at all, and likewise triple clamps. This is probably why I gave up on it before. I have no idea what a triple tree is supposed to be.--Rocknrollmancer (talk) 03:25, 6 March 2016 (UTC)

External links modified (February 2018)
Hello fellow Wikipedians,

I have just modified one external link on Motorcycle fork. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://archive.is/20130204111913/http://tonyfoale.com/Articles/Dive/DIVE.htm to http://tonyfoale.com/Articles/Dive/DIVE.htm

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 13:05, 6 February 2018 (UTC)

What is so ambiguous?

 * 1) Please stop with the "Americanism" slurs, unless you're prepared to tell us exactly what UK English terminology we should be using and why it is so much better.
 * 2) A triple tree is three things: an upper triple clamp, a steering stem, and a lower triple clamp. It's called a "tree" because the stem and clamps look like a trunk and branches.
 * 3) Want to make it better? Leave the lead alone and write some more details about clamps, steering heads, and steering stems in the body of the article. --Dennis Bratland (talk) 20:51, 11 March 2018 (UTC)