Well, I thought I did "elucidate" my argument -- gyroscope ... in-/stability ... that is, if you are trying to turn the wheel and the lateral instability of the softer spokes of a double butted lacing allows the wheel to momentarily continue in a given direction from where the rider is directing the bike.ScienceIsCool said:Alfeng, if you have an argument to make and wish to counter the prevailing wisdom, you would do well to elucidate. As it is, I think you've confused two terms. Lateral stiffness and strength.
The lateral stiffness of any wheel is defined by the following elements:
- beam stiffness of the unsupported rim between spokes (second moment of inertia)
- bending stiffness of each spoke (related directly to the second moment of inertia). For a round spoke, this is dependent on diameter. For aero spokes it's a bit more complicated.
- number of spokes.
- to a very tiny degree, wheel stiffness is affected by the number of spoke crossings. Empirically, the lateral stiffness is measured to go down with the number of spoke crossings. I.e., radial wheel is laterally stiffer than a 3x
So it could very well be that the straight guage spoked wheel is laterally stiffer than a double butted spoked wheel. Then again, it might not. There's a few variables to consider.
I would define the strength of a wheel is it's ability to handle riding conditions without breaking. Swaging a spoke (double butting) allows you to put more material is high stress zones such as the elbow and threads. It also allows you to take material away from the central portion where it is not needed. I could see how this would indeed make a stronger wheel.
Lastly, the experts are often recognized as such for a reason. It's important to question any claim (it's a great way to learn and discover), but to stand in a public forum and say they are wrong... I'd suggest that you have a very clear argument why that would be the case.
John Swanson
www.bikephysics.com
I am basing MY observation on first-hand experience. Empirical evidence with noodly lacing which was NOT noticeable when moving in a straight line ... granted, an extreme. Reproducable if one is daring or foolish.
Anecdotal, but number crunching by me would certainly NOT satisfy you ... so, why should I bother?
CONSIDER THIS:
Skiers, for example, know that a stiffer ski is easier to control.
A stiffer ski boot is also a benefit to control.
Yet, a soft ski is easier to control at bunny hill speeds by a novice or inexperienced skier who doesn't know how to set his/her edges ... so, that is what they use. They just don't know better, and the speeds at which they are traveling are not handicapped by the soft skis.
If that doesn't make sense then I have to say that if you can't think out of the conventional wisdom box which you have apparently trapped yourself inside of and "work with me" on this ... then, I can't expand upon this further because I won't be able to convince you ... and, as I have said before, it doesn't matter to me whether someone incorrectly chooses to think that a double butted lacing is better ...
As I said, I used double butted spokes in a wheel I laced for myself this past Spring ... but, I know the potential limitations ... I know how the wheel is going to be used.
John, you're the one into doing the math ... MY contrary-to-the-conventional-wisdom shouldn't be the basis for your investigation ... your curiosity should be enough motivation.
ONE MORE TIME, for a beach cruiser or townie then a double butted lacing is the BEST ... but, those are the bikes that won't have that lacing due to the premium one has to pay for the double butted spokes.
So, I say the emporer has no clothes. That's just the way I see it. If you can't see it, then I can understand why you wouldn't want to crunch the numbers.
Let the TRUE BELIEVERS continue to worship their sacred cow and say I am a heretic ... its the way of the world.