Talk:Bicycle wheel

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Contents

[edit] To do

  • Discuss spoke patterns: radial vs. tangential
- Already covered in Wheelbuilding article -AndrewDressel 13:22, 16 August 2006 (UTC)
  • Strength to weight ratio
  • construction
    • rim
    • hub
    • spokes
- Done -AndrewDressel 14:45, 21 August 2006 (UTC)

Extlink: http://www.exploratorium.edu/cycling/wheel1.html

--Christopherlin 21:44, 17 Apr 2005 (UTC)

Why is there no mention of disc wheels? Rather major piece missing from the article. Mathmo 11:45, 13 September 2006 (UTC)

By all means, please add a mention. -AndrewDressel 14:23, 13 September 2006 (UTC)

[edit] Reaction to load

"The hub does not "hang" from the the top spokes."

I don't have either of the books cited, wish I did. Is this a direct quote or paraphrase? It would seem to me that if the tension if the spokes above the hub is higher than the tension in the spokes below the hub, then the hub does in fact "hang" from the upper spokes. It certainly does not "rest" on the lower spokes if they are under tension. -AndrewDressel 15:36, 17 August 2006 (UTC)

No, it's not a direct quote. If you compared a wheel not under load and one under radial load, the only significant change of spoke tension is that the spokes directly under the hub becomes more slack. So in effect the hub does "rest" on the lower spokes, but because they are in tension, the load is taken by those spokes becoming looser. This can be demonstrated by plucking the spokes which will indicate any change in tension, as mentioned in "The Bicycle Wheel". LDHan 17:47, 17 August 2006 (UTC)
So it is just semantics. I'd say that if the spokes below are under tension and not compression, then the hub is definitely not resting on them. If the spokes above are in sension, then the hub is definitely hanging from them. That's just my understanding of the terms "hang" and "rest". Anyway, as I've learned, wikipedia is not about "truth" but about "verifiability". I'd stick with a direct quotation in this case. -AndrewDressel 02:23, 19 August 2006 (UTC)
If you use the phrase the bottom spokes increase in compression instead of bottom spokes decrease in tension (both are same), and that the top spokes do not change tension, then it might be more clear that the hub does not "hang" from the upper spokes. LDHan 10:07, 19 August 2006 (UTC)
That's where we disagree. My understanding of the terms is that a member cannot be in compression until the tension become negative, and visa versa. Both are opposite and relative to the rest state. -AndrewDressel 01:33, 20 August 2006 (UTC)
THE WHEEL STANDS ON ITS SPOKES ... the wheel is not supported by the bottom spokes only. Without the rest of the spokes, the bottom ones would have no tension. Standing, in this case, means that the spokes at the bottom are the ones that change stress; they are being shortened and respond structurally as rigid columns. Quote from The Bicycle Wheel, Jobst Brandt.
The hub clearly does not hang from the upper spokes or they would show an increase in tension. The four or so spokes (in 36 spoke wheel) between the hub and ground are the only ones that show any significant change by becoming shorter when the wheel is loaded. Jobst Brandt, May 1 1999, post no 51: http://groups.google.com/group/rec.bicycles.tech/browse_frm/thread/72d637cde5e3875b/b058acb2c64d0900?tvc=1&q=+hang++spokes+Jobst+Brandt++#b058acb2c64d0900
LDHan 10:07, 19 August 2006 (UTC)
So it really does boil down to semantics. What is the definition of "compression", "tension", "stand", and "hang"? I suggest you use direct quotations heavily. -AndrewDressel 01:33, 20 August 2006 (UTC)
OK, I'll remove the "hang" sentence, and let the facts speak for themselves. LDHan 11:57, 20 August 2006 (UTC)
Take out the bottom 8 spokes of a wheel and put your weight on it. The wheel will still support your weight. A wheel _does_ 'hang' from the top spokes. Ender8282 08:23, 23 April 2007 (UTC)
How does one put a spoke under compression if the nipple has nothing substantial to bear on? In a good, old-fashioned, conventional wheel, the nipple is separated from the inner tube by a strip of bias tape. The inner tube rests on the bias tape. If the pressure in the inner tube is 100 psi, a 3/16" diameter nipple head will only allow for a bearing load of about 2.75 lb per spoke. I don't remember the exact buckling load of a typical spoke (I determined it about 30 years ago) but it's in the same general range. If you work out the resultant vertical component of force in the lower spokes working together, that doesn't provide enough force to carry a typical rider.
With a more modern design, using a hollow rim, the nipple head doesn't even touch the inner tube or tubular tire. In this case, there is no load carrying capacity in compression - the spoke will move if the tension reduces to zero (barring a bit of stiction between the nipple and the rim).
In fact, the upper spokes do carry a substantial part of the load. The remaining spokes provide stability to the rim and the rim carries the load to the ground.
This doesn't apply to solid wheels or spokes rigidly attached to the rim, as with one-piece CFRP designs.
Michael Daly 06:36, 22 July 2007 (UTC)

[edit] Wooden rims

Caption to Image:Bamboobike.jpg claims that the rims are wooden... I doubt this and there is no mention of it in the image summary. They look like rusted steel to me. Have messaged the image uploaded but consider this a request for any other input. bad·monkey talk to the {:() :: 05:55, 3 April 2007 (UTC)

Yes, the wooden bit is actualy the tyre. If there were no metal rim as well, then how would the metal spokes be fixed to the rim securely enough perform well?Gregorydavid 13:10, 3 April 2007 (UTC)
In fact it is highly likely that the rims are made from wood. Wood was the most popular material for rims around that time and metal rims only became popular (on safeties) with the rise of rim brakes (which this bicycle does not have). The tires are certainly not wood, they are pneumatic rubber types, the valves are visible coming out of the rims. Will.law 17:13, 3 April 2007 (UTC)
Wood definitely have been used for making rims. LDHan 21:42, 3 April 2007 (UTC)
The fact that wood has been used for rims is not in question; merely what this picture is of. If you look around where the rim meets the tyre (which is most certainly not wood!), you can see shine and reflections which give it the appearance of metal to me. bad·monkey talk to the {:() :: 03:39, 4 April 2007 (UTC)
It's not that clear from the photo, but it could be tarnished metal. LDHan 09:51, 4 April 2007 (UTC)

As the image uploader I cannot solve the problem definately because the pic was taken a few years ago, very far from where I live and with a poor camera resolution. The only thing I can tell is that if there had been sthg unusual about the wheels, i would probably have noticed that and included it in the image summary. So it seems the wheels were made as they mostly are today - steel and rubber. other clues are what seem to be reflections on the rims and possible technological problems with joining wood with obviously metal spokes. Personally, I would opt for removing the example from the article until some Wikipedian from Holešovice in Prague goes for a nice walk to the nearby Technological Museum and finds out the Truth ;-) Mohylek 13:43, 5 April 2007 (UTC)

Here is the image again for another look -
Bicycle with rims made of wood (1896)
Bicycle with rims made of wood (1896)
Gregorydavid 13:28, 6 April 2007 (UTC)
Sorry, wrong wheel, no wood on these rims. Gregorydavid 13:39, 6 April 2007 (UTC)
  • It does not look like a wooden rim so the caption is wrong.
  • There is nothing that allows the wheel to stand out from the rest of the bike. I don't see what purpose that picture serves.
  • I can supply a picture of JUST a bicycle wheel. I also have pictures of hubs. I am new to this and don't know how to post an image. Respond with a link or send me directions to ender8282@yahoo.com. Ender8282 08:29, 23 April 2007 (UTC)

[edit] Hub

I made a bunch of changes to the hub section. Any feedback/editing would be welcome.
If anyone would like to talk about coaster brake hubs and internally geared hubs I would love someone else describing them.
Ender8282 08:34, 23 April 2007 (UTC)

[edit] Reaction to inertia

concerns about rotational inertia of bicycle wheels are vastly overstated--the inertia of all bicycle wheels is negligible compared to the mass of the rider.

Can you back this up with any data or references. Have you ridden wheels with low and high moments? There _is_ a noticeable difference when accelerating and climbing.
Ender8282 19:03, 23 April 2007 (UTC)

See the article at http://www.velonews.com/tech/report/articles/9662.0.html
I am not sure that I believe everything that it says but I do agree with some of it.
Ender8282 19:56, 23 April 2007 (UTC)

[edit] Rims with no holes for spokes?

At time of writing, the article says:

The number of spoke holes on the rim normally matches the number of spoke holes in the hub. Some unusual rim designs have no holes for spokes, for example Campagnolo road rims and the Velocity Zvino MTB rims.

Huh - Campagnolo rims (presumably, the rims used on Campy's own wheels) don't have spoke holes? Both my sets do! Which wheels don't use holes for spokes? If it is just a few designs, we should probably say "...for example some Campagnolo road rims...". —The preceding unsigned comment was added by WikianJim (talk • contribs) 20:12, 15 May 2007 (UTC).

Anyone? WikianJim 19:22, 28 May 2007 (UTC)
Here's some info on the Zvino [[1]] & [[2]]. I think saying that they don't have holes is misleading though. The rim still has holes, just in a separate section of the rim. AFAIK, campagnolo rims all have spoke/nipple holes. Just not in the 2nd layer of aluminum so you don't have to use rim tape. Will.law 14:59, 30 May 2007 (UTC)
Right, I get this now! On a double wall rim they have holes for the nipples to poke through, but not on the bit that touches the innertube/tubular. WikianJim 16:03, 1 June 2007 (UTC)

There are more companies than just velocity and campy that make whls without holes in the outer wall. Mavic (CrossMax, XM819 rims, Kyrsium & R-SYS) Shimano (DA road tubeless whls) Falcrum (I am not sure but since they are asian made campagnolo whls I suspect) It is a little hard deciding what brands/models to list and which not to list. I suspect that Mavic was first to market but I am not sure. Do we want to try to make a list of all of them or should we choose one or two as references? Is it possible to have a NPOV if we list some but not others? —Preceding unsigned comment added by Ender8282 (talk • contribs) 04:30, 3 April 2008 (UTC)

[edit] Clincher is not quite the right term

Clincher is a specific type of tire-rim design that is obsolete. What is usually referred to today as a "clincher" is in fact a wire-on or wire-type design. Clinchers have a bead that grips a hooked edge on the rim when the tire is under pressure. Wire-type simply rely on wire tension to offset the pressure and the tire is held on the rim by being slightly smaller than the rim.

Reference: Sharp, Archibald, "Bicycles & Tricycles, An Elementary Treatise on Their Design and Construction", Longmans, Green, 1896 pp495-497 (Reprinted MIT Press, 1979).
Michael Daly 06:49, 22 July 2007 (UTC)

Sheldon Brown seems to agree, although he may be using the same original source: http://www.sheldonbrown.com/gloss_cl.html.
Probably due to a shortage of sources on such topics :). Bicycling magazine made a big deal about this about 30 years ago, but the naming conventions don't seem to have been affected. Michael Daly 16:36, 22 July 2007 (UTC)

ISO 8090 (“Cycles – Glossary of terms”) lists the following types of rims along with drawings:

  • straight-sided rim
  • hook bead rim
  • sprint rim; adhesive bond rim
  • Westwood rim
  • double chamber crochet rim
  • single chamber crochet rim

There is no mention of “clincher”. Markus Kuhn (talk) 22:45, 31 December 2007 (UTC)

The article discusses different methods of measuring beaded-edge and wired-edge tires, but does not define the distinction between a bead and a wire or say which is more common in which contexts. Seems to me, in an encyclopedia intended for ordinary people to read, the latter points are more important. Jim.henderson (talk) 17:43, 22 January 2008 (UTC)