On Sat, 25 Aug 2007 11:19:51 -0700, in rec.bicycles.tech JeffWills
<
[email protected]> wrote:
>Trigonometry, my dear boy. The distance from hub center to the flange
>gives you the base of the triangle where the vertical distance from
>the hub to the rim is the height and the spoke forms the hypotenuse.
>Without knowing this measurement, you can't correctly determine the
>spoke length.
>
>Many hubs (most rear and some front) are not symmetrical right-to-
>left. You need to determine the distance from center to flange on each
>side to get the lengths exactly right. It can make a difference-
>highly dished rear wheels can have a difference of 2mm from left to
>right.
>
>Try using Spocalc: http://sheldonbrown.com/rinard/spocalc.htm . The
>spreadsheet includes data on many common rims and hubs, and allows
>independant data entry for items not included. It's never let me down.
>
>Jeff
Ya know, my dear boy, what we need are four points:
>Trigonometry, my dear boy. The distance from hub center to the flange
>gives you the base of the triangle...
A distance alone does not give you the base of a triangle... if you
knew trig, dear boy, then you'd already know that; if all you have is
distance, you're not in Euclidean space yet, so it's nonsensical to
start talking about triangles until you unequivocally fix three
noncolinear points. (Actually, I think you're fixing two and taking a
perpendicular delta, but that's not what you wrote.)
Useless post. Go back and review your undergraduate trig and don't
address me as "my dear boy" until you're sure that you know your
subject... I'm pretty well up to date on my trig... "dear boy".
Jones
