Talk:Spoke

Other uses of spokes
Incidentally... old bent bicycle spokes are sometimes kept in toolkits
 * They are useful for unblocking plugs etc.
 * They may be used as lockpicks.
 * A cardboard splash guard inserted in pletcher rack can be prevented from sagging by sticking in a couple of spokes, which shouldn't be too bent. The cardboard must extend to the end of the rear wheel to keep the seat of your pants dry and the mud stripe off your back. Metarhyme 23:47, 30 December 2006 (UTC)

How to compute the spoke length formula using a calculator
The spoke length formula is only as accurate as your fingers are at data input and manipulation. Switch the calculator to scientific mode: View -> Scientific. Use a pencil with an eraser to write down the hub's spoke hole diameter and the ERD (effective rim diameter, or the circle made by the ends of the spokes in a built wheel). Write down the flange from center distance (a) as well. Half of the hub diameter is radius one and half of the ERD is radius two, write these down, too. Input the degrees according to the cross number and the number of spokes, then get the cosine. Multiply that by 2, by radius one and by radius two. Put that in memory and clear the display. Input radius one -> square -> plus -> input radius two -> square -> plus -> input a -> square -> equals; then subtract -> memory recall -> equals. Then to get that figure's square root, put a tick in the [ ] Inv box and x^2 should give you a non-ridiculous spoke length. Run it several times to be sure that you did not make a mistake.

''Great directions! Indeed, it took me two or three tries with the calculator to get the right, non-ridiculous result. Erm, why do you need an eraser on the pencil?'' --RainerBlome 22:53, 23 December 2005 (UTC)


 * The eraser is to impeach and convict offensive pencilings prior to replacing them with pencilings that better reflect truth. Metarhyme 21:42, 25 December 2005 (UTC)

Contradiction?
This statement: "The load on the hub causes the wheel rim to flatten slightly against the ground as the lowermost pre-tensioned spoke shortens and compresses by losing some of its pre-tension. Despite the common misconception that a bicycle wheel "hangs" from its upper spokes, the upper spokes show no significant change in tension."

appears to contradict this statement: "Tangential spoking has several desirable effects: The maximum load is being taken by two spokes at any time rather than by only one."

Is there a reference for either one? The Bicycle wheel seems to confirm the first statement. Without a reference, the second one, the 'desirable effect' one should go. -AndrewDressel 02:08, 22 August 2006 (UTC)


 * Okay. Out it comes. -AndrewDressel 01:49, 23 August 2006 (UTC)

history of spokes
Can we get a section (or at least something) on the development/history of spokes? When did people stop using solid wheels and convert over to spokes and why? That sort of thing. Reinventing the wheel and such. Ornen (talk) 03:26, 1 September 2008 (UTC)

Tioga
It was actually Sugino who made the disc and sold them under the Sugino brand, Tioga just resold them under their Tioga brand name with mass marketing. Here is the patent http://www.google.com/patents?id=TkEhAAAAEBAJ&pg=PA3&dq=United+States+Patent+5064250#v=onepage&q=United%20States%20Patent%205064250&f=false

--Bensimmo (talk) 09:47, 30 October 2009 (UTC)

Calculation
Does anyone have any first hand experience with this equation (the one now on the spoke article page, used to determine length of a bicycle wheel.):
 * $$l = \sqrt{ a^2 + {r_1}^2 + {r_2}^2 - 2 \, r_1 r_2 \cos(\alpha)} $$

I mean has anyone built a bicycle wheel after choosing spokes based on it's output. I've been messing around with it for a while now, and it has been consistently giving me 10.7mm longer lengths than my usual method (an excel file from sheldonbrown.com) when I changed the ERD but leaving the other variables the same. I did it for 6 different ERDs and all of them came out 10.7mm longer. Some random googleing brought me this, that does produce the same results as the equation we've got posted here. Could very well be that I'm overlooking something obvious, but thought I'd look for input. --Keithonearth (talk) 07:19, 13 December 2009 (UTC)
 * Well, I have to admit that I did make a stupid mistake, and that's the main reason that the numbers were coming out different. I had the calculator set to radians.  oops.  So now the numbers are very close to the excel file's output, but still a mm or two off.  I'd be happier if they were the same, or I understood the reason for the difference, but I guess the numbers the equation is giving us could be right.  I'll have to build a wheel or two from the math.  --Keithonearth (talk) 21:39, 16 January 2010 (UTC)
 * If a wheel is well tensioned, there will be both elastic and inelastic strain - the formula doesn't provide for this stretching, which is slight. At the moment, Sapin is willing to point, under their Calculate by hand heading, to the formula on the article page - a quality endorsement. Having the end of the spoke stop exactly where you thought it would in the nipple can be accomplished, but nudging the formula needs figuring Kilograms of force exerted over effective length of diameter of spoke. Straight guage 2 mm spokes have a radius of one, which simplifies exponentiation in the modulus of elasticity of steel formula. Skipping that, you can guess that the length will be shorter than the ideal mathematical distance, but by exactly how much depends. - 173.24.245.10 (talk) 07:55, 8 April 2012 (UTC) (Sapin replaced their spoke calculator page, removing the calculate by hand reference.) - 173.24.245.10 (talk) 20:00, 12 August 2012 (UTC)

It is essential to get correct dimensions of rim and hub to get a good estimate of spoke length. Here is an aid to trusting your own measurements: measure rim and hub  A 2 mm diameter spoke will stretch very little but stretch is a factor with strained skinny spokes. The modulus of elasticity of steel is 21,000 Kilograms per square millimeter; strain equals tension divided by elasticity. You want to divide the stress (kgf) to be applied to the spoke by the elasticity of the spoke. The elasticity is π × spoke radius mm^2 × 21,000 ÷ effective length in mm. - 173.24.113.190 (talk) 08:01, 30 November 2018 (UTC)

Number of spokes
The number of spokes in a wheel (or the size of the angle between one spoke and another) affects the deformation of the wheel, and is a trade-off between wheel size, total weight, construction complexity and rigidity of the materials used.


 * Is this only about compression spokes, the section into which the sentence was inserted, or all spokes. -AndrewDressel (talk) 16:18, 13 September 2010 (UTC)

Kick scooter wheels with fewer spokes will give a "bumpier" ride than ones with many spokes.


 * Is this true of all spoke-wheeled vehicles, or just kick scooters. If the latter, why? Either way, why is it so, and can we find a source? -AndrewDressel (talk) 16:18, 13 September 2010 (UTC)

Radial spoke calculation
The calculation for the length of radial spokes:

$$l = \sqrt{ a^2 + (r_2-r_1)^2 }$$

seemed to be incorrect, as a, the angle between the flange hole and the rim hole, is by definition 0 for radial spokes; this equation is not dimensionally consistent anyway. Based on trigonometry and comparison to the equation for crossed spokes, it should be:

$$l = \sqrt{ d^2 + (r_2-r_1)^2 }$$

where d is the center-to-flange distance. I changed it, but forgot to leave an edit comment (and not logged in!), so here's my explanation.

Also, based on definition of spoke length, r3 should be in the radial wheel version also.

$$l = \sqrt{ d^2 + (r_2-r_1)^2 } - r_3$$

Withlyn (talk) 21:46, 8 June 2011 (UTC)


 * Both correct and taken care of. --RainerBlome (talk) 22:34, 15 October 2018 (UTC)

usual spoke diameters table error?
I don't believe the "section areas" are correct.

The formula for the area of a circle is pi * (radius^2). The table has the "section area" as the square of the diameter.

For example, a diameter of 2mm is listed as having a "section area" of 4mm^2. The radius of 2mm diameter is 1mm. pi*(1^2) is 3.14mm^2 and some change.

Perhaps a spoke pro who knows math can verify that "section area" actually means the "area of the cross section" of the spoke instead of being an industry idiom. Shiropinkus (talk) 07:45, 7 June 2015 (UTC)

Spoked wheel?
Typing "spoked wheel" into Wikipedia only brings you to a page about some Indian author, and the only way to find this page is by searching for "spoke". That seems problematic to me. Even if you assume "spoke" and "spoked wheel" are parts of each other, there should at least be a redirect to this page or something. AnnaGoFast (talk) 07:44, 19 January 2018 (UTC)
 * Done: spoked wheel. -AndrewDressel (talk) 12:12, 20 January 2018 (UTC)

Chalcolithic paintings of spoked wheels in India
This passage


 * Notes


 * References

The earliest evidence for spoked wheels comes from the Sintashta culture, at ca. 2000 BCE; spoked wheels in India before 2000 BCE is wishfull thinking. Joshua Jonathan - Let's talk!  04:55, 15 July 2021 (UTC)

Neumayer himself dates them at 1800-1200 BCE; See: See also Celeste Paxton (2016), in Voices from the past: Researcher explores a mystery across 40 centuries "neo-chalcolithic," 2300-1000 BCE. That is, Late Harappan c.q. Aryan migration period, or even early Vedic period: chariots introduced by the Aryans. Joshua Jonathan - Let's talk!  05:10, 15 July 2021 (UTC)
 * harappa.com, Chariots in the Chalcolithic Rock Art of India
 * harappa.com, Chariots in the Chalcolithic Rock Art of India

Fibre spokes
There is no direct mention of tension only individual fibre spokes for bicycles. These are available commercially and dedicated enthusiasts also DIY them. The primary reason given for their use is the weight saving when compared to similar strength metal spokes. One commercial brand is Berd PolyLight but there may be others.

Idyllic press (talk) 10:15, 19 September 2021 (UTC)