Jobst, lied, about rudge rims

[thirty-six]

On 11 Oct 2007, 03:25, jobst.bra...@stanfordalumni.org wrote:
> Carl Fogel writes:
> >>>>>>> [...]
> >>>>>>>> no, excessively compressed rims more readily fold.
> >>>>>>> Suppose the rim is highly compressed by high spoke tension.
> >>>>>> I don't understand what you mean by this.
> >>>>> Just that the spokes are pulling the rim inward compressing it.
> >>>>> [...]
> >>>>>>> Is this right/wrong/too simplistic?
> >>>>>> I think you can test this on your own wheels (if they don't have
> >>>>>> fewer than 20 spokes) by having someone pluck spokes while you
> >>>>>> stand on one pedal and lean the bicycle with both feet in the
> >>>>>> pedals as in riding while standing. You'll notice that the bottom
> >>>>>> spokes of the wheels lose tension unequally, the "upperside" ones
> >>>>>> losing more tension than the "underside" spokes.
> >>>>> Interesting, but my question was about something else-- how spoke
> >>>>> tension affects what happens to the rim when you hit a bump.
> >>>> As was mentioned in another thread, a rim is an elastically supported
> >>>> beam and acts like a railroad track supported by elastic cross ties.
> >>>> By performing a linear mental development of the circularwheelinto a
> >>>> linear one, some of these effects are more readily apparent.
> >>>> Consider the spokes as not becoming slack and that they have an axial
> >>>> elasticity. The deflections (changes in tension and length) require
> >>>> forces that make rim shape mainly irrelevant. Deflections are on the
> >>>> scale of 0.001's of inches as you can see in the diagrams of FEA
> >>>> analysis. You can easily deform a bare rim radially with thumb
> >>>> pressure but you can't do that on a completewheelwhere spoke
> >>>> stiffness is the measure. Please look at the deflection diagrams that
> >>>> make this clear.
> >>> Dear Jobst,
> >>> How much does a bare deep modern rim deform under thumb pressure?
> >> Oh several times as much as a standard cross section rim 36 spokedwheel,
> >> 0.050" at least. As I said, the RIM.
> >>> I used to think that bare bicycle rims with no spokes flattened quite
> >>> easily, but posts on RBT and turn-of-the century factory claims that a
> >>> man could stand on a bare no-spoke highwheeler rim have made me wonder
> >>> about this.
> >> They lied. Even though those were steel rims, many were U-shaped flat
> >> material. You can sit on a bare MA-2 but it deforms enormously
> >> (about 1.5").
> >>> I don't have any bare rims, so I'm curious if anyone can put a 10 or
> >>> 20 pound weight on some aero-style hoops and report what happens.
> >> I don't have any deep-V rims either, but its not anything like a
> >> spokedwheel, whose radial rigidity is almost entirely the support
> >> element elasticity (the spokes). Didn't you recently assess what that
> >> was?
> >>> I expect that bare no-spoke rims deform more than a tensionedwheel,
> >>> but I have to admit that I've never tried the experiment and don't
> >>> know what to expect--a tenth of an inch, an inch, two inches, a bent
> >>> rim?
> >> Well, my MA-2 did not take a set after I sat on it.
> > Dear Jobst,
> > Sigh... What a nice post, except for where you call people you don't
> > know liars about something that you've never tested.
>
> This is a deception of the second kind. As I said most high wheelers
> used U-shaped rims of flat sheet metal. That you cannot crush a
> deep-V rim with body weight is likewise true except that hollow cross
> section penny-farthing bicycle were uncommon and therefore do not
> represent the norm. In that respect, the claim is false and as you
> pointed out, exceptions don't make the rule.
>
> > Here's whatRudgewrote about their 1887 highwheeler:
> > "The FELLOES are of the Clement hollow pattern, consisting of one
> > piece of steel tubing rolled and pressed into the proper shape, and
> > capable of bearing a weight of two hundred pounds, even before a
> > single spoke has been inserted."
> > http://tallbike.com/tall/87rudge.html
> > Why not consider the possibility that you may not know everything?
>
> Why not consider thatRudgewas not the maker of most high wheels and
> that even these were out of the ordinary.
>
> > And why not consider what readers will think when you callRudgeliars
> > when I mention that their bare highwheel would support the weight of a
> > man, but then go on to state that your aluminum MA2 supported your 180
> > pound weight without taking a set, dropping a whole inch and a half
> > when you sat on it?
>
> Where did I maneRudgeas liars? I find your application of
> translation to what others post unseemly and an obvious personal
> attack. I also notice that you don't write such responses to those
> who pass disinformation to the newsgroup in rudest manner.
>
> > For all I know, you might even be right, but it's awfully hard to
> > credit you when you take such a bizarre approach.
>
> What is bizarre is your take on these things. The information is in
> what I wrote but you choose to cite an exception in spite of my
> explanation to what rims I was referring. I sense that you have a bit
> of jim beam disorder at work from your harsh comments to most anything
> I write.
>
> Jobst Brandt

Rudge-Whitworth were the largest manufacturer of tension wheels in
England. They were the development of the Coventry Machinists Company
of who built the Aerial wheel designed by Starley, THE high wheel
maker. See other posting about Times newspaper reference.