broken spokes, cassette/drive train compatability

Michael Press writes:

Be aware that using an undersized tube is a risk. A risk
that is not worth taking. An undersized tube inflated
expands to fill the space allotted. It is blown up like a
balloon. The tube walls are in tension. If (or when) the
tube is punctured it can rip and deflate instantly. At
speed you might lose control.

This seems unlikely, the pressure required to increase an undersized
inner tube from its nominal size to that of the tire being minimal.


Joe

Michael Press wrote:


A properly sized tube is already the size of the space it
is intended to fill, when inflated the tube is the same
size as when deflated, and the walls are not in tension.

That statement is untrue. No tube fully fills the space inside a tire
and the rim well, until it is inflated, so the walls are indeed in
tension. The amount of tension is certainly higher in an undersized
tube, and I would agree that makes it more likely to flat suddenly.

--
Ted Bennett

Ted Bennett wrote:
Michael Press wrote:


A properly sized tube is already the size of the space it
is intended to fill, when inflated the tube is the same
size as when deflated, and the walls are not in tension.

That statement is untrue. No tube fully fills the space inside a tire
and the rim well, until it is inflated, so the walls are indeed in
tension. The amount of tension is certainly higher in an undersized
tube, and I would agree that makes it more likely to flat suddenly.

--

Agreed! How else could indiviual tubes be designed (as they are) to fit
a range of different tire sizes?

I am not sure about my rim width, but it seems to have always worked
with
a 700x35 tube. I recently replaced it with a tube that is marked
700x20-28.
Do you think the (presumably) wide rim/narrow tube combiantion could
bring broken spokes? I might have to be more cautions here. When the
tiny tube is fully inflated, the valve does not fully stick out of the
rim,
looking very funny.
I've asked at bike shops about spoke breakage they tell me that after
one breaks they all tend to go.In my experiece this is frequently(but
not always)true.

On 9 Nov 2005 09:55:41 -0800, "Mister2u" wrote:
I am not sure about my rim width, but it seems to have always worked
with
a 700x35 tube. I recently replaced it with a tube that is marked
700x20-28.
Do you think the (presumably) wide rim/narrow tube combiantion could
bring broken spokes? I might have to be more cautions here. When the
tiny tube is fully inflated, the valve does not fully stick out of the
rim,
looking very funny.
I've asked at bike shops about spoke breakage they tell me that after
one breaks they all tend to go.In my experiece this is frequently(but
not always)true.

If you replace a few, and then within a few months more go, it's time to
respoke the wheel.

Jasper

On Sat, 05 Nov 2005 10:30:41 -0800, jim beam wrote:

wow, by that rationale, every car, washing machine, every computer,
every elevator motor, every air conditioning compressor, [insert any
number of mass production processes here] would be utter garbage. but
they're not.

They pretty much are, compared to the same built with a lot of attention
to detail, time, and usage of the same materials and fabrication
techniques.

That a car built that way costs 100-500.000 bucks instead of 20 is beside
the point.

Jasper

On 5 Nov 2005 18:52:01 -0800, "D'ohBoy" wrote:
wrote:
... humans are able to sense spoke twist ...

A mark on one side of the spoke from a sharpie (or other marking pen)
will make it visually obvious....

Not to a machine, though. That is, it's possible to devise machinery that
can see it, but it's not on the current generation of machines.

Jasper

Jasper Janssen writes:

... humans are able to sense spoke twist ...

A mark on one side of the spoke from a Sharpie (or other marking
pen) will make it visually obvious...

Not to a machine, though. That is, it's possible to devise
machinery that can see it, but it's not on the current generation of
machines.

We don't want no steenkin' seeing machines! The solution to the
problem is dirt simple and used by manual skilled manual builders. A
machine can do this much more easily.

When I think how many years I badgered the wheel building machine
people about their "problem". They were so proud of their machines
that they couldn't hear that wheels that came off their machines were
less than ideally built.

Spoke prep! You must be blind to invent spoke glue and not recognize
the problem that did not exist before building wheels with machines...
especially when you are the guys who lowered the tension setting.

Jobst Brandt

wrote:
Jasper Janssen writes:


... humans are able to sense spoke twist ...


A mark on one side of the spoke from a Sharpie (or other marking
pen) will make it visually obvious...


Not to a machine, though. That is, it's possible to devise
machinery that can see it, but it's not on the current generation of
machines.


We don't want no steenkin' seeing machines! The solution to the
problem is dirt simple and used by manual skilled manual builders. A
machine can do this much more easily.

When I think how many years I badgered the wheel building machine
people about their "problem". They were so proud of their machines
that they couldn't hear that wheels that came off their machines were
less than ideally built.

they weren't listening to you? i can't say i care to listen to a guy
who's so amazingly deficient in his theory either, regardless of their
bluster or bullying.


Spoke prep! You must be blind to invent spoke glue

er, jobst, you know about wheel dish, right? you know, in the kind of
wheels you don't ride? and you know about lateral loading? good! then
you'll know that non-drive side spokes can completely detension at drive
side spoke tensions that are required to mitigate rim cracking. as you
/do/ know, if spokes detension, they unscrew. and a thread locker, be
it loctite, nylock, spoke prep or whatever, /is/ beneficial to the long
term trueness & reliability of a modern highly dished wheel if it
prevents spokes unscrewing!

and not recognize
the problem that did not exist before building wheels with machines...
especially when you are the guys who lowered the tension setting.

Jobst Brandt