What's up with rim? - Page 2

On 09 Jul 2004 16:32:23 +0100 (BST), David Damerell
<damerell@chiark.greenend.org.uk> wrote:

>jim beam <nospam@example.net> wrote:
>>Alex Rodriguez wrote:
>>>Get a copy of 'The Bicycle Wheel' by Jobst Brandt and you
>>>won't have to look for a decent builder. You can do it
>>>yourself.
>>http://www.sheldonbrown.com/wheelbuild.html is better.
>
>That axe sharp enough yet, sock puppet boy?
>
>Anyone using Sheldon's page should note that it does not
>mention the need to install a rim tape before tensioning.

Dear David,

Anyone using Jobst's book should note the same thing, unless
something about rim tape was added in his third edition.

On page 102, Jobst does say:

"WARNING

Tensioning spokes can be dangerous. A spoke that ruptures
under tension can be shot from the rim into your eye, like
an arrow from a crossbow. Never face directly into the line
of the spokes while working on the wheel."

This sounds like better safety advice than hoping that a rim
tape will stop a broken spoke.

I'm tempted to experiment with a pair of bolt cutters, but
I'm hoping that someone like Sheldon Brown or Andrew Muzi
with piles of wheels, yards of rim tape, and inquiring minds
will experiment and let us know whether rim tape will indeed
stop a well-tensioned spoke cut near the elbow, the most
common kind of failure.

On the one hand, broken spokes don't puncture inner tubes,
so the force of broken spoke may not be very high. A much
broader crossbow bolt, after all, will easily go through the
gentle reader and his twin brother.

On the other hand, the human eye has a pressure of only
around 22mm Hg and is somewhat more delicate and difficult
to repair or replace than a high-pressure bicycle tube.

"Caution: do not look into laser with remaining eyeball."

Carl Fogel

jim beam wrote:

> Benjamin Lewis wrote:
>> jim beam wrote:
>>
>>> Alex Rodriguez wrote:
>>>
>>>> Get a copy of 'The Bicycle Wheel' by Jobst Brandt and
>>>> you won't have to look for a decent builder. You can do
>>>> it yourself. --------------
>>>
>>> http://www.sheldonbrown.com/wheelbuild.html is better.
>> Mmm, petulant resentment. My favourite!
>>
> interesting in depth analysis.
>
> sheldon's site is superb and it doesn't cost anyone a dime
> to read.

I agree.

> i don't see why stating that opinion would be a problem.

It wouldn't have been. They're both excellent resources.

--
Benjamin Lewis

Don't take life so serious, son, it ain't nohow permanent.
-- Walt Kelly

carlfogel@comcast.net wrote:

> <damerell@chiark.greenend.org.uk> wrote:
>>
>> Anyone using Sheldon's page should note that it does not
>> mention the need to install a rim tape before tensioning.
>
> Dear David,
>
> Anyone using Jobst's book should note the same thing,
> unless something about rim tape was added in his third
> edition.
>
> On page 102, Jobst does say:
>
> "WARNING
>
> Tensioning spokes can be dangerous. A spoke that ruptures
> under tension can be shot from the rim into your eye, like
> an arrow from a crossbow. Never face directly into the
> line of the spokes while working on the wheel."
>
> This sounds like better safety advice than hoping that a
> rim tape will stop a broken spoke.

From the 3rd edition, page 95:

WARNING Tensioning spokes can be dangerous. A spoke can
rupture under tension and shoot from the rim, like an arrow
from a crossbow, into your eye. Never face directly into the
line of the spokes while tensioning a wheel. Installing a
rim tape now will prevent this from occurring.

--
Benjamin Lewis

Don't take life so serious, son, it ain't nohow permanent.
-- Walt Kelly

carlfogel@comcast.net wrote:

>
> I'm tempted to experiment with a pair of bolt cutters, but
> I'm hoping that someone like Sheldon Brown or Andrew Muzi
> with piles of wheels, yards of rim tape, and inquiring
> minds will experiment and let us know whether rim tape
> will indeed stop a well-tensioned spoke cut near the
> elbow, the most common kind of failure.
>
>

plastic rimtape works fine, suddenly cutting a spoke from
a well tensioned wheel is a good way to make your
audience jump

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL www.m-gineering.nl

On Sat, 10 Jul 2004 00:18:30 -0700, Benjamin Lewis
<bclewis@cs.sfu.ca> wrote:

>carlfogel@comcast.net wrote:
>
>> <damerell@chiark.greenend.org.uk> wrote:
>>>
>>> Anyone using Sheldon's page should note that it does not
>>> mention the need to install a rim tape before
>>> tensioning.
>>
>> Dear David,
>>
>> Anyone using Jobst's book should note the same thing,
>> unless something about rim tape was added in his third
>> edition.
>>
>> On page 102, Jobst does say:
>>
>> "WARNING
>>
>> Tensioning spokes can be dangerous. A spoke that ruptures
>> under tension can be shot from the rim into your eye,
>> like an arrow from a crossbow. Never face directly into
>> the line of the spokes while working on the wheel."
>>
>> This sounds like better safety advice than hoping that a
>> rim tape will stop a broken spoke.
>
>From the 3rd edition, page 95:
>
>WARNING Tensioning spokes can be dangerous. A spoke can
>rupture under tension and shoot from the rim, like an arrow
>from a crossbow, into your eye. Never face directly into
>the line of the spokes while tensioning a wheel. Installing
>a rim tape now will prevent this from occurring.

Dear Benjamin,

You warm the heart of a hopeless textual pedant!

I'm excited--it sounds as if Jobst's 3rd edition either
moved and expanded the warning, shortened itself 7 pages
from 102 to 95, or suffered the fate of the carelessly
numbered First Folio, in which the pages of "Hamlet" run
from 152 to 156 and then 257 to 282:

http://shea.mit.edu/ramparts/comment...what_is_a_fol-
io/pagenumbers/pagenumbers.htm http://dewey.library.upenn.e-
du/sceti/printedbooksNew/index.cfm?TextID=hamlet_f1&PagePos-
ition=5 http://dewey.library.upenn.edu/sceti/printedbooksNe-
w/index.cfm?TextID=hamlet_f1&PagePosition=6

In Jobst's second edition, Fig. 56 "Centering the wheel"
shows a naked wheel--has the fig leaf of a rim tape been
added to this line drawing in the third edition to cover up
the exposed spoke nipples?

(Thomas Bowdler did this to the saucier sections of Shakespeare--
at least the ones that he recognized--so I'm curious if the
wheel drawings in Jobst's book were updated to match the
added rim-tape text.)

From your newer quote of Jobst and from what Marten says
elsewhere in this thread, it sounds as if a mere rim tape
will stop a spoke that breaks during wheel-building.

Still, I'm half-hoping that someone with a Rolf tensioned to
around 500 pounds will sacrifice a spoke with a pair of bolt-
cutters and let us know if the fury of modern high-tension
low-count spokes can be restrained by a spoke.

I haven't heard of broken spokes puncturing tubes, so I'm
guessing that the results won't be dramatic, but nothing
beats a practical demonstration.

Thanks,

Carl Fogel

carlfogel@comcast.net wrote:

> In Jobst's second edition, Fig. 56 "Centering the wheel"
> shows a naked wheel--has the fig leaf of a rim tape been
> added to this line drawing in the third edition to cover
> up the exposed spoke nipples?

No, it has not. It's also now Fig. 55. I wonder what figure
has been moved or expurgated?

> (Thomas Bowdler did this to the saucier sections of Shakespeare--
> at least the ones that he recognized--so I'm curious if
> the wheel drawings in Jobst's book were updated to match
> the added rim-tape text.)

I think I'd classify the rim-tape text as "helpful
suggestion" rather than "dire warning".

> Still, I'm half-hoping that someone with a Rolf tensioned
> to around 500 pounds will sacrifice a spoke with a pair of
> bolt-cutters and let us know if the fury of modern high-
> tension low-count spokes can be restrained by a spoke.

If a video could be provided, it would be even more fun.

--
Benjamin Lewis

Although the moon is smaller than the earth, it is
farther away.

On Sat, 10 Jul 2004 12:09:32 -0600, carlfogel@comcast.net wrote:
>shows a naked wheel--has the fig leaf of a rim tape been
>added to this line drawing in the third edition to cover up
>the exposed spoke nipples?

Stop, you're turning me on.

>bolt-cutters and let us know if the fury of modern

Why get your fury involved?

>high-tension low-count spokes can be restrained by a spoke.

I'm sure a spoke could be restrained by a properly-applied
spoke. Maybe if you coil the spoke into a wire-cone (didn't
pop singer Madonna wear a bra with cups made of wire-cones?)
and place it above the spoke-hole.
--
Rick Onanian