Tied and soldered spokes.

Ian Smith wrote:
On Sat, 21 Nov 2009 20:16:35 +0000, Naqerj wrote:
Ian Smith wrote:
On Fri, 20 Nov, wrote:
On Nov 21, 3:38 am, Ian Smith wrote:
Out of interest, however, has anyone ever seen a purely radial
buckle on a bicycle wheel?
I've dented a rim wall (think severe pinch flat territory). Does
that count?
I don't think so. In fact, it would tend to demonstrate the case that
they don't happen - you can hit the rim hard enough to cause plastic
material failure and no radial buckle occurred.
Like James, I've dented a rim wall but without buckling the rim as a
whole - I have seen a radial buckle, but in a motor cycle wheel. I
reckon it is possible to radial buckle a wheel but you have to hit it
very hard indeed. The other thing with a pedal cycle wheel is that to
get a purely radial buckle you'd not only have to hit it very hard, but
also dead square, otherwise it will buckle laterally as well. Then you
could argue for days about whether that counts as a radial buckle.

It would be relatively simple to determine whether it was a radial
buckle - you'd need to plot distance of rim from hub centre and
see if you had an elastic-type variation from constant, then destress
the wheel and see if it recovers.

Every lateral buckle I've seen on a bicycle wheel looks like a
near-enough purely lateral buckle - the 'pringles' look. I don't
think you can load a bicycle wheel on a bicycle to a level that causes
a radial buckle without first triggering either a plastic failure, or
a lateral buckle.

Ah, we're not talking about quite the same thing, I think. The motor
cycle wheel I saw had a plastic failure of the rim - the rim ended up
heart-shaped.

--
Andrew

thirty-six wrote:
On 22 Nov, 18:08, Ian Smith wrote:

Likewise, I think you'll always get a lateral buckle from a wheel
before you get a radial buckle.

If always, then wheels have too poor a lateral stability.

The other way round: it that the radial stability than is greater than
strictly necessary, rather than lateral stability being poor. Even
lateral stability is greater than necessary - a bicycle wheel works
perfectly well in a tricycle, which subjects it to more lateral force
than a bicycle does.

The high proportion of radial stability compared to lateral is pretty
much determined by the shape of the space the wheel has to fit into.

--
Andrew

On 23 Nov, 22:29, Naqerj wrote:
Ian Smith wrote:
On Sat, 21 Nov 2009 20:16:35 +0000, Naqerj wrote:
*Ian Smith wrote:
On Fri, 20 Nov, wrote:
*On Nov 21, 3:38 am, Ian Smith wrote:
Out of interest, however, has anyone ever seen a purely radial
buckle on a bicycle wheel?
*I've dented a rim wall (think severe pinch flat territory). Does
*that count?
I don't think so. *In fact, it would tend to demonstrate the case that
they don't happen - you can hit the rim hard enough to cause plastic
material failure and no radial buckle occurred.
*Like James, I've dented a rim wall but without buckling the rim as a
*whole - I have seen a radial buckle, but in a motor cycle wheel. *I
*reckon it is possible to radial buckle a wheel but you have to hit it
*very hard indeed. *The other thing with a pedal cycle wheel is that to
*get a purely radial buckle you'd not only have to hit it very hard, but
*also dead square, otherwise it will buckle laterally as well. *Then you
*could argue for days about whether that counts as a radial buckle.

It would be relatively simple to determine whether it was a radial
buckle - you'd need to plot distance of rim from hub centre and
see if you had an elastic-type variation from constant, then destress
the wheel and see if it recovers.

Every lateral buckle I've seen on a bicycle wheel looks like a
near-enough purely lateral buckle - the 'pringles' look. *I don't
think you can load a bicycle wheel on a bicycle to a level that causes
a radial buckle without first triggering either a plastic failure, or
a lateral buckle.

Ah, we're not talking about quite the same thing, I think. *The motor
cycle wheel I saw had a plastic failure of the rim - the rim ended up
heart-shaped.


Which doesn't mean it was not radially buckled and it is still a cycle
wheel.

On 23 Nov, 22:40, Naqerj wrote:
thirty-six wrote:
On 22 Nov, 18:08, Ian Smith wrote:

Likewise, I think you'll always get a lateral buckle from a wheel
before you get a radial buckle.

If always, then wheels have too poor a lateral stability.

The other way round: it that the radial stability than is greater than
strictly necessary, rather than lateral stability being poor.

I dont comprehend this. ^


*Even
lateral stability is greater than necessary - a bicycle wheel works
perfectly well in a tricycle, which subjects it to more lateral force
than a bicycle does.

A tricycle wheel usually has cantilever axles which are thicker and
flange offset is greater on the dual track axle. A bicycle wheel can
only be used for the single track axle, if the machine is ridden hard.


The high proportion of radial stability compared to lateral is pretty
much determined by the shape of the space the wheel has to fit into.

If the 3" flange spacing on 27/28" wheels was determined to be good a
century ago and so standardized then, then it's good for today.
Materials have changed. Specifically the choice of stainless spokes.
These require specific attention if they are to match the performance
of carbon steel spokes.

"thirty-six" wrote in message
...

Materials have changed. Specifically the choice of stainless spokes.
These require specific attention if they are to match the performance
of carbon steel spokes.

Filing notches or applying strong acid?

The weird thing is despite the peculiarities of your build process, your
wheels probably turn out ok, because you probably do put enough tension in
them rather than the low value you claim to. Come to Settle and I'll measure
your spoke tension. The riding here is good - lots of steep hills to
practice descending on.

On 24 Nov, 03:19, "Clive George" wrote:
"thirty-six" wrote in message

...

Materials have changed. *Specifically the choice of stainless spokes.
These require specific attention if they are to match the performance
of carbon steel spokes.

Filing notches or applying strong acid?

The weird thing is despite the peculiarities of your build process, your
wheels probably turn out ok, because you probably do put enough tension in
them rather than the low value you claim to. Come to Settle and I'll measure
your spoke tension. The riding here is good - lots of steep hills to
practice descending on.

i'VE ASSESSED tension using musical pitch and it equated to 170lbf
for a 36 spoke heavy duty sprint wheel usin g 15swg carbon steel
spokes. But I dont build to a tension. I build to a desired wheel
response. Stop being obsessed about spoke tension, it is wheel
response which is important, not some number on a hoogywotsit. There
is an ideal spoke tension which is best determined through testing of
the completed wheel. I use a cobbled road if I am unsure after using
static load testing.

thirty-six wrote:

i'VE ASSESSED tension using musical pitch and it equated to 170lbf
for a 36 spoke heavy duty sprint wheel usin g 15swg carbon steel
spokes.


How do you get from pitch to lbf?

It's got me baffled, you must have some amazing testing gear.


--
Its never too late to reinvent the bicycle

On 25 Nov, 10:41, Keitht KeithT wrote:
thirty-six wrote:
i'VE ASSESSED *tension using musical pitch and it equated to 170lbf
for a 36 spoke heavy duty sprint wheel usin g 15swg carbon steel
spokes. *

How do you get from pitch to lbf?

It's got me baffled, you must have some amazing testing gear.

--
Its never too late to reinvent the bicycle

A micrometer to check the spoke gauge at 14swg (0.080DIA) a steel
ruler to check spoke length (12") and a chromatic tuner with a clip
on microphone to measure musical pitch. Of course I don't need to use
any of these to build wheels to excellent standards. It is though,
nice to check the wheel, following a few good whacks, with the tuner
to see that its stability has remained. Very slight variences are
sometimes observed but have not been more than 15% of a semitone and
dont get any worse if left. It is necessary in this instance to
accurately balance pitch in the first place using the tuner so as to
provide a reference pitch.

On Wed, 25 Nov 2009 10:41:27 -0000, Keitht KeithT wrote:

thirty-six wrote:

i'VE ASSESSED tension using musical pitch and it equated to 170lbf
for a 36 spoke heavy duty sprint wheel usin g 15swg carbon steel
spokes.


How do you get from pitch to lbf?

It's got me baffled, you must have some amazing testing gear.

I know you probably weren't expecting a serious answer, but there is one:

http://hyperphysics.phy-astr.gsu.edu...es/string.html

Should work pretty well if you use guitar strings (preferably unwound) in
place of spokes.

How well it works for double butted I wouldn't like to guess, but it
should get you in the right ball park.

--

Rob

On 25 Nov, 12:51, thirty-six wrote:
On 25 Nov, 10:41, Keitht KeithT wrote:

thirty-six wrote:
i'VE ASSESSED *tension using musical pitch and it equated to 170lbf
for a 36 spoke heavy duty sprint wheel usin g 15swg carbon steel
spokes. *

How do you get from pitch to lbf?

It's got me baffled, you must have some amazing testing gear.

--
Its never too late to reinvent the bicycle

A micrometer to check the spoke gauge at 14swg (0.080DIA) a steel
ruler to check spoke length (12") and a chromatic *tuner with a clip
on microphone to measure musical pitch. *Of course I don't need to use
any of these to build wheels to excellent standards. *It is though,
nice to check the wheel, following a few good whacks, with the tuner
to see that its stability has remained. *Very slight variences are
sometimes observed but have not been more than 15% of a semitone and
dont get any worse if left. *It is necessary in this instance to
accurately balance pitch in the first place using the tuner so as to
provide a reference pitch.

Forgot to answer your put question. I used a table to give the
frequency of the musical pitch notation indicated on my £5 Lidl
tuner. I then used an algerbraic formula to determine the tension in
the wire based on its weight, length and frequency IIRC. The actual
tension of the spoke makes no difference to me because I work well
within the safe stresses of the materials in hand. If I was to build
up wheels will stupid light rims, as well as using steel washers, I
would make some calculations on wether the resulting spoke tension
could be continually carried by the rim. I have been happy to build
28 spoke and up wheels without recourse to measuring spoke tension or
calculation. A lightweight 24 spoke is pushing it for me because I
dont have the experience with these rare rims.