Talk:Bicycle wheel

From Wikipedia, the free encyclopedia

This article is part of WikiProject Cycling, an attempt to build a comprehensive and detailed guide to cycling on Wikipedia. If you would like to participate, you can edit the article attached to this page, or visit the project page, where you can join the project and/or contribute to the discussion.

[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)