M
Michael Press
Guest
In article
<955a21b6-30f9-428d-8d97-a9e24c633baa@u69g2000hse.googlegroups.com>,
datakoll <[email protected]> wrote:
> On Mar 12, 12:08 am, Michael Press <[email protected]> wrote:
> > In article <[email protected]>,
> > John Everett <[email protected]> wrote:
> >
> > > Even though I've now ordered the spokes I was writing about when I
> > > started the ERD thread, I still never received a clear answer to my
> > > original question. Let me rephrase:
> >
> > > Should ERD actually be the diameter of the circle defined by the ends
> > > of the spokes in the built wheel?
> >
> > It is the diameter of the circle defined by the outermost
> > surface of the nipples. Many spoke calculators aim to get
> > the end of the spoke to or almost to that circle, even taking
> > into account the elastic elongation of the spoke.
> >
> > > If so, should the end of the spokes
> > > theoretically be even with the top of the nipple, or buried somewhere
> > > inside the nipple? If buried, should they be even with the outside
> > > surface of the rim holes, or even with the bottom of the screwdriver
> > > slot?
> >
> > > Note that we're talking about millimeter differences here, which
> > > strikes me as a bit like discussing the number of angels the can dance
> > > on the head of a pin. ;-)
> >
> > Do not ignore small corrections. They can add up
> > and leave you with a situation that will take
> > you far longer to remedy than the initial time
> > investment in getting it right. People who know,
> > know what can be ignored because the have calculated
> > the error bounds far closer than one millimeter.
> >
> > > I've re-rimmed wheels with rims that were
> > > 5mm larger in published ERD than the originals without problems. Makes
> > > me wonder how many nipple threads actually need to be engaged to build
> > > a safe wheel.
> >
> > Asking me? All of them.
> >
> > > I'm guessing from Jobst's response in my OP's thread that ERD is
> > > precisely defined in "The Bicycle Wheel", but I've managed to build a
> > > number of wheels without ever reading it.
> >
> > Are you asking for our advice?
>
> See here's another one.
> YO MATH WHIZ ? if ERD is a diameter then why are rear spokes in two
> lengths ?
Is this a trick question?
The rim is not centered at the mid-point of the two hub flanges.
ERD is measured in the mid-plane of the rim, not along the spokes.
Here is one for you. How is it that anything can float in water?
--
Michael Press
<955a21b6-30f9-428d-8d97-a9e24c633baa@u69g2000hse.googlegroups.com>,
datakoll <[email protected]> wrote:
> On Mar 12, 12:08 am, Michael Press <[email protected]> wrote:
> > In article <[email protected]>,
> > John Everett <[email protected]> wrote:
> >
> > > Even though I've now ordered the spokes I was writing about when I
> > > started the ERD thread, I still never received a clear answer to my
> > > original question. Let me rephrase:
> >
> > > Should ERD actually be the diameter of the circle defined by the ends
> > > of the spokes in the built wheel?
> >
> > It is the diameter of the circle defined by the outermost
> > surface of the nipples. Many spoke calculators aim to get
> > the end of the spoke to or almost to that circle, even taking
> > into account the elastic elongation of the spoke.
> >
> > > If so, should the end of the spokes
> > > theoretically be even with the top of the nipple, or buried somewhere
> > > inside the nipple? If buried, should they be even with the outside
> > > surface of the rim holes, or even with the bottom of the screwdriver
> > > slot?
> >
> > > Note that we're talking about millimeter differences here, which
> > > strikes me as a bit like discussing the number of angels the can dance
> > > on the head of a pin. ;-)
> >
> > Do not ignore small corrections. They can add up
> > and leave you with a situation that will take
> > you far longer to remedy than the initial time
> > investment in getting it right. People who know,
> > know what can be ignored because the have calculated
> > the error bounds far closer than one millimeter.
> >
> > > I've re-rimmed wheels with rims that were
> > > 5mm larger in published ERD than the originals without problems. Makes
> > > me wonder how many nipple threads actually need to be engaged to build
> > > a safe wheel.
> >
> > Asking me? All of them.
> >
> > > I'm guessing from Jobst's response in my OP's thread that ERD is
> > > precisely defined in "The Bicycle Wheel", but I've managed to build a
> > > number of wheels without ever reading it.
> >
> > Are you asking for our advice?
>
> See here's another one.
> YO MATH WHIZ ? if ERD is a diameter then why are rear spokes in two
> lengths ?
Is this a trick question?
The rim is not centered at the mid-point of the two hub flanges.
ERD is measured in the mid-plane of the rim, not along the spokes.
Here is one for you. How is it that anything can float in water?
--
Michael Press