Talk:Derailleur gears

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Contents 1 Invention decade? 2 Meaning of "Derailleur" 3 Really Early Campagnolo 4 All Campy? 5 Merge Jockey Wheel into here 6 Jockey Wheel Terminology 7 Friction shifting versus indexed? 8 What Rotor System might have been? 9 Album name "Disraeli Gears" did come from "Derailleur Gears"

[edit] Invention decade?

Are you sure that derailleurs were perfected by the 1930's? I did a bit of googling on the issue and it seems that Tour de France riders weren't using them until after WWII, and even in the 1950's the gear systems were very primitive compared with modern derailleurs. --Robert Merkel 00:38 Mar 27, 2003 (UTC)

This is where I found my information *http://www.exploratorium.edu/cycling/gears1.html It could be wrong of course, although Its possible that derailleur gears were reasonably well developed by the 1930s, but usage didn't become cheap/widespread until the 1950s. I think the fact that Tour de France riders didn't use them until the 1950s might be because many riders looked down upon multi-geared bicycles and viewed them as an unnecesary mechanical complication. G-Man 18:32 27/3/2003 UTC

How could Degrange make his quip in 1902 if the derailleur wasn't invented until 1905? One of these dates must be wrong. Lisiate 09:16, 13 Aug 2003 (UTC)

Good point. The derailleur as we know it today wasn't really invented until after WW II, but Degrange made his famous quip in 1902 because:

• The 1905 derailleur was not the first - various other derailleurs existed back before the turn of the century, and
• Companies like Sturmey-Archer (founded 1902) were making variable gear systems based on Internal hub gears (instead of derailleurs) AHands 12:20, 13 Aug 2003 (UTC)

I believe the Campagnolo Gran Sport was the first modern parallelogram dual jockey wheel derailleur in 1951. There were derailleurs before, but not with the combination of dual jockey wheels and parallelogram. Older derailleurs used various mechanisms to derail hte chain, sometimes slider mechanisms with a jockey wheel, sometimes paddles that weren't in contact except durin shifting, parallelogram not being necessary to be a derailleur. If I rememeber, I'll do a bit more research and polish something to clarify. --Pqdave 17:37, 1 Dec 2004 (UTC)

The subsequent section I started Talk:Derailleur_gears#Really_Early_Campagnolo meanders a bit, but I eventually sorted out some history, and there's a few citations there. Basically, racers adopted derailleurs later than tourists, for various reasons.--SportWagon 22:54, 18 August 2006 (UTC)

[edit] Meaning of "Derailleur"

What does "Derailleur" mean? Is it named after an inventor, or is it a (for example) French language word? — Matt Crypto 17:51, 14 May 2006 (UTC)

From the article "When a rider operates the lever, the changes in cable tension move the derailleur from side to side, "derailing" the chain onto different gears." So they're named after how they operate. Lisiate 20:52, 14 May 2006 (UTC)

And yes, it is a French language word. Sheldon Brown has an explanation here: http://www.sheldonbrown.com/derailer.html (along with arguing for the anglicisation of the word.) -- Blorg 15:33, 14 July 2006 (UTC)

[edit] Really Early Campagnolo

Someone who has owned a succession of bike shops in Toronto owns, or at least once owned, a Legnano bicycle with a Camapagnolo three-speed derailleur system of sorts. I think it dates from the late forties or early fifties.

There were no jockey wheels--the rear dropouts were instead unusually long, and the wheel itself moved to adjust the chain slackness. To change gears you loosened the rear axle using an underseat lever which was connected to the rear-wheel quick-release. You then arranged to make the wheel move forwards or backwards in the dropouts--a rack-and-pinion mechanism maintained side-to-side alignment of the wheel. (Perhaps you actually cranked something to cause the movement; I'm not sure about that detail). You had a derailleur of sorts; little more than a spade attached to a separate lever under the seat. You used that to persuade the chain to move to the appropriate one of the three sprockets available. From memory (as is this whole recollection) the sprockets were all relatively large, and did not vary more than six, possibly only four, teeth from smallest to largest. (I'd guess 17-20-23). After everything was positioned properly for your new gear, you tightened up the remote-control quick-release and could once again ride with full pressure.

I should try and track down more Internet documentation of this, or perhaps contact the person I mention.--SportWagon 19:11, 9 August 2006 (UTC)

These derailleurs were the Cambio Corsa or later Paris-Roubaix derailleurs. http://www.campyonly.com/history.html --SportWagon 19:19, 9 August 2006 (UTC)

So, I am suggesting that "Some early designs used a system of rods to move the chain onto various gears." be expanded with more details. Did Campagnolo have competitors? Was the parallelogram design with jockey wheels delayed by regulations which effectively prohibited jockey wheels in competition? Etc.--SportWagon 19:23, 9 August 2006 (UTC)

John Forester's history of the derailleur http://probicycle.com/jf/jfderail.html - seems that Campagnolo had "something" to get introduced into top-level racing, even though others, principally Simplex, had workable reasonably modern (compared to the Cambio Corsa and Paris-Roubaix) designs much earlier.--SportWagon 19:39, 9 August 2006 (UTC)

Reading of Forester above suggests (Simplex) derailleurs were allowed in the Tour de France in 1938, but still did not become the norm then. It didn't seem to be until the scary Cambio Corsa and similar short-lived Paris-Roubaix derailleurs, soon followed by the (now) "conventional" Gran Sport, that derailleurs really caught on in such top-level competition. Note that a two-speed "flippable" hub with no jockey wheels allowed at least one of the gears to be a "fixed wheel" (no freewheel)--an advantage up hills.--SportWagon 19:51, 9 August 2006 (UTC)

History of derailleur (racing) http://www.theracingbicycle.com/Tullio.html - more balanced than Campag-oriented reference above, suggests, e.g. Coppi did use Simplex derailleurs in 1947 Tour de France.--SportWagon 20:05, 9 August 2006 (UTC)

Perhaps a more detailed description of Cambio Corsa and Paris-Roubaix would fit into Multi-speed versus single-speed (possibly renaming that section--Jockey wheels or no jockey-wheels, perhaps?). One can surmise (but evidence should be found) that Campagnolo was trying to get the advantages of both single gear and derailleur with his systems. --SportWagon 20:10, 9 August 2006 (UTC)

Surveying the web a bit, the problem is people (myself included) see the Cambio Corsa system, and think "that looks primitive", and assume therefore it predates essentially modern rear derailleur systems, whereas in fact it did not. After some overcoming of tradition and bigotry, the modern derailleur took over. Well, perhaps increases in robustness made it more suitable for racing. (Tourists could stop to clean or oil, but racers couldn't).--SportWagon 20:17, 9 August 2006 (UTC)

here is an illustration of that Campy jockeyless derailleur, circa 1946. That website has quite a lot of interesting historical bike-stuff. If you snoop around a bit, you'll see Huret direct-parallelogram derailleurs of 1948. And here is a bunch of scans from old Peugeout catalogs, showing bikes with parallelogram derailleurs as early as 1935. adamrice 21:21, 14 August 2006 (UTC)

http://www.m-gineering.nl/oldtech.htm (from Derailleur gears External Links) contains, among other things, a picture of a Paris-Roubaix derailleur on a bicycle equipped with four rear sprockets.--SportWagon 18:40, 15 August 2006 (UTC)

[edit] All Campy?

for several decades true racing bicycles were all Campy,

A quick search suggests, but doesn't fully confirm, that French firms such as Mercier ridden by Jacques Anquetil would use Simplex equipment in the Tour de France.--SportWagon 19:56, 9 August 2006 (UTC)

Quote for several decades true racing bicycles were all Campy, meaning that drivetrain groupset — the derailleurs, shifters, hub, cassette and chain — were all manufactured by the Campagnolo company.

Clearly not true. Simplex, Huret, Galli, Mavic, Gipiemme, Zeus, Suntour have all made derailleurs, and it's only recently that Campagnolo made chains, or had chains made with its name. LDHan 19:13, 14 August 2006 (UTC)

[edit] Merge Jockey Wheel into here

Because Jockey wheel is so short, I have copied the current version here for easy reference.

Jockey wheel - The upper of two pulleys housed in the lower cage of the rear derailleur (or rear mech) of a bicycle. (The lower one is called the "tension pulley.") The derailer pulleys are usually constructed of plastic, and often have teeth that makes them look a bit like sprockets. The cage which houses the pulleys is hinged at the main body of the derailer, and its purpose is to take up the slack on the chain. The cage is sprung to force it clockwise, as viewed from the right, thus keeping tension on the chain through the range of gears.

Modern derailer pulleys usually consist of a plastic cog, two metal dust caps, a central bushing of steel or brass and the fixing screw (which also holds the two sides of the derailer cage together). The jockey pulley has a tendency to work themselves loose, so the fixing bolt should be tighened securely, and the threads lubricated with grease or coated in a thread-locking compound to prevent this happening.

IMHO, this article (Derailleur gears) contains ample information about jockey wheels (contradicting Jockey wheel in at least one detail, however). However, the Jockey wheel article goes on to give detailed mechanical description and maintenance tips which I would think not appropriate for the Derailleur gears article. Would it be appropriate to include those tips here, or would it be appropriate to merely say those tips are not really within the scope of Wikipedia? If neither of those is an option, the Jockey wheel article should continue to exist. (Note also idiosyncratic spelling "derailer").--SportWagon 21:10, 9 August 2006 (UTC)

I now see the References for this article (Derailleur gears) contain

• Bicycle Repair in Wikibooks

That, combined with the lack of repair tips in this article, suggests to me that repair tips are not appropriate in Wikipedia--SportWagon 21:25, 9 August 2006 (UTC)

Yes, merge it. Not every sub-component of a bike needs its own article, and if the jockey-wheel article stands, I will be forced to start articles on the headset crown race, water-bottle boss, etc. adamrice 21:04, 14 August 2006 (UTC)

I am arguing that the merge could be accomplished by simply deleting the Jockey wheel article. With all due respect for Sheldon Brown, I think his nomenclatural assertions in that article are personal preferences only, for which counter-examples of less strict usage could be found. And I have suggested that maintenance tips are not appropriate to include in any wikipedia article, but belong instead only in wikibooks. But I solicit multiple opinions.--SportWagon 21:20, 14 August 2006 (UTC)

Alright, even worse, an alternate, and still relatively strict, terminology of jockey wheels, guide pulley and tension pulley is suggested in the current article. (Derailleur gears)--SportWagon 21:23, 14 August 2006 (UTC)

[edit] Jockey Wheel Terminology

Okay, I guess we should separate the terminology debate from the actual merge debate. A quick Google ought to convince us that many people use "jockey wheels" (or "jockey pulleys") to refer to the pair of pulleys in question.

Google also led me to a probably useful source of information.

• http://www.freepatentsonline.com/search.html

At that site, it appears that "jockey" is not used very much at all in reference to bicycles (and in at least one instance did match Sheldon Brown's contention--but in the same reference gave the alternate of "guide pulley"). "guide" and "tensioner" pulleys appear common in the patent descriptions.--SportWagon 21:44, 14 August 2006 (UTC)

[edit] Friction shifting versus indexed?

With friction shifting, the rider first moves the lever enough for the chain to jump to the next sprocket, and then adjusts the lever a slight amount to center the chain. An indexed shifter has distinct clicks for each gear, and the rider merely moves the lever to the click they want without a second adjustment movement.

I think that passage exaggerates the degree to which you need to over-shift with friction. More realistically, you would frequently do a shift, and then later realize perhaps you needed a fine adjustment. On a particular bike, you might eventually learn to habitually overshift and back-adjust for certain shifts. A casual rider could usually get away without such adjustments, although when riding hard it was important to keep the chain properly centered to avoid unnecessary friction or slippage. The passage also overlooks the fact that achieving that over-shifting is actually a fairly difficult problem in the design of indexed shifting. Bah. I should try a test ride some time. Unfortunately the only bicycle I have ready-to-run without indexed shifting has no shifting at all! I'll think about the above and edit sometime, probably. I should also write off-line and then upload a "Cambio-Corsa/Paris-Roubaix Diversion" section.--SportWagon 18:24, 25 September 2006 (UTC)

The amount of over-shifting needed varies depending on the design of the derailleur and freewheel sprockets. With the older ones like Campagagnolo Super Record, you definitely need to over-shift then re-centre, especially if you use older freewheels that don't have modern shaped sprockets, but it's something that becomes automatic after you get used to it. LDHan 21:53, 25 September 2006 (UTC)

(Using this as a bit of a scratch-pad...) Over-shifting was more necessary on shifts to larger sprockets. Shifting to smaller sprockets usually happened before the chain was centered, so you merely needed to cause the clunk, then smooth it out, usually continuing to shift in the same direction. The Sedi-Sport and similar chains helped a lot before ramped clusters. Though designed for narrowly-spaced clusters, the Sedi-Sport even worked nicely with old-standard spaced (5-speed) freewheels. My first setup was a cheap Simplex rear derailleur and and Atom freewheel with a who-knows-what chain. The levers needed not infrequent tightening while riding, and the rod-mechanism of the front derailleur (it was cable operated, but the cage itself was pushed out on a small rod) occasionally needed a little tap from your toe to persuade it to go back to the small ring. I seriously think the over-shifting phenomenon is more of a factor in the successful design of indexed systems than it was a conscious hassle for humans.--SportWagon 16:34, 26 September 2006 (UTC)

[edit] What Rotor System might have been?

I recently deleted from See-Also:

*[[Rotor system]] <!-- what is this? -->

There is no such article Rotor system. But after thinking about it for a while someone may have been hoping to create and link to an article about "automatic" shifting driven by weights moved by centrifugal force. The name would be too general for such an article, anyway.--SportWagon 16:15, 27 September 2006 (UTC)

[edit] Album name "Disraeli Gears" did come from "Derailleur Gears"

Reading Disraeli Gears you see...

• The title of the album was an inside joke. Clapton had been thinking of getting a racing bike and was discussing it with Baker, when Mick Turner, one of the roadies, commented on the performance of "those Disraeli gears", meaning to say "derailleur gears". The band thought this was hilarious and decided that it should be the title of their next album. Had it not been for the roadie's malapropism, the album would simply have been entitled Cream.

So it wasn't a totally inappropriate link. Not that I feel strongly enough about it to put the link back...

"Just FYI".--SportWagon 17:31, 27 November 2006 (UTC)