Cup & Cone Bottom Brackets - Any Sources?

On Sat, 29 Mar 2008 15:32:25 GMT, still just me
wrote:

On Fri, 28 Mar 2008 22:28:35 -0700, jim beam
wrote:


otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. or aluminum. or carbon. as
someone that like to express opinion on these materials, the least you
should do is bother to actually use them.

otooh, but fixing a frame that is otherwise still serviceable he not
only avoids wasting resources but keeps a valued old friend by his
side for years to come.

Not everyone buys into the throwaway world or has to always run with
the supposedly latest and greatest.


OOTH = OTGH

In article ,
still just me wrote:

On Fri, 28 Mar 2008 22:28:35 -0700, jim beam
wrote:


otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. or aluminum. or carbon. as
someone that like to express opinion on these materials, the least you
should do is bother to actually use them.

otooh, but fixing a frame that is otherwise still serviceable he not
only avoids wasting resources but keeps a valued old friend by his
side for years to come.

Not everyone buys into the throwaway world or has to always run with
the supposedly latest and greatest.

Of course, since you're goal wasn't really to comment intelligently on
the thread, but instead just to flame Jobst, I guess that's
irrelevant.

jim beam is a salesman in the `real world.'

--
Michael Press

John Thompson wrote:
On 2008-03-29, jim beam wrote:

otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. or aluminum. or carbon.

How do you "wear out" a frame? Damage, yes -- either through neglect or
abuse, or what have you. But "wear out?"

Corrosion (metal frames), fatigue (metal and composite) and degradation
of epoxy and adhesives (composite).

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

On Mar 31, 5:10*pm, John Thompson wrote:
On 2008-03-31, Tom Sherman wrote:

John Thompson wrote:

How do you "wear out" a frame? Damage, yes -- either through neglect or
abuse, or what have you. But "wear out?"
Corrosion (metal frames),

I'd file that under "neglect."

fatigue (metal and composite)

Not an issue with a properly designed steel frame, but certainly a
potential issue with aluminum. I'm not aware of composites having
fatigue failures, but I may just be ignorant on that point.

and degradation of epoxy and adhesives (composite).

Disposable frames, then. I'll stick with steel, thank you.

Steel as a material has an infinite fatigue life with the loads
applied by whimpy cyclists, but as actually used in bicycle frames, it
does not -- at least based on my experience. I have cracked a number
of steel frames -- probably due to overheating of the lugs or some
other glitch in fabrication. My longest surviving high mileage frame
is a 1986 Cannondale T1000. That's old school aluminum. I am not so
sure about the new stuff. My brother's Orbea even gives me even less
confidence -- based solely on the tap-tap test. As a big guy, I find
it hard to trust something that light. -- Jay Beattie.

John Thompson wrote:
On 2008-03-31, Tom Sherman wrote:
John Thompson wrote:
How do you "wear out" a frame? Damage, yes -- either through neglect or
abuse, or what have you. But "wear out?"

Corrosion (metal frames),

I'd file that under "neglect."

fatigue (metal and composite)

Not an issue with a properly designed steel frame, but certainly a
potential issue with aluminum. I'm not aware of composites having
fatigue failures, but I may just be ignorant on that point.

fatigue characteristics of cfrp are much superior to that of a high
strength steel that has no endurance limit. and guess what: quality
steel bike frames are /not/ made from the cheaper low strength stuff
that always exhibits such behavior.




and degradation of epoxy and adhesives (composite).

Disposable frames, then. I'll stick with steel, thank you.


steel is disposable. especially when it's deployed in ways that fail to
address design issues that other materials can much more easily mitigate
[oversize tube being the prime example].

still just me wrote:
On Fri, 28 Mar 2008 22:28:35 -0700, jim beam
wrote:

otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. or aluminum. or carbon. as
someone that like to express opinion on these materials, the least you
should do is bother to actually use them.

otooh, but fixing a frame that is otherwise still serviceable he not
only avoids wasting resources but keeps a valued old friend by his
side for years to come.

nonsensical claptrap.



Not everyone buys into the throwaway world or has to always run with
the supposedly latest and greatest.

see above.



Of course, since you're goal wasn't really to comment intelligently on
the thread, but instead just to flame Jobst, I guess that's
irrelevant.

i really don't give a flying one about who says what. i state the
facts. repairing an old frame with known flaws is a failed opportunity
to gain first hand experience of improvements that have occurred in the
last 3+ decades of frame design and manufacture. and for someone that
purports to be qualified to comment on engineering design and materials,
to /not/ do so is actually negligent.

John Thompson wrote:
On 2008-03-29, jim beam wrote:

otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. or aluminum. or carbon.

How do you "wear out" a frame? Damage, yes -- either through neglect or
abuse, or what have you. But "wear out?"


what part of jobst's "involuntarily threadless BB" is inconsistent with
a frame wearing out?

On Mar 31, 10:01*pm, jim beam wrote:
John Thompson wrote:
On 2008-03-29, jim beam wrote:

otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. *or aluminum. *or carbon..

How do you "wear out" a frame? Damage, yes -- either through neglect or
abuse, or what have you. But "wear out?"

what part of jobst's "involuntarily threadless BB" is inconsistent with
a frame wearing out?

normal stuff

Michael Press wrote:
In article ,
still just me wrote:

On Fri, 28 Mar 2008 22:28:35 -0700, jim beam
wrote:

otoh, by not simply replacing a worn out frame, you're deliberately
avoiding bothering to research improvements in frame design such as
over-size tube which help mitigate shimmy. or aluminum. or carbon. as
someone that like to express opinion on these materials, the least you
should do is bother to actually use them.
otooh, but fixing a frame that is otherwise still serviceable he not
only avoids wasting resources but keeps a valued old friend by his
side for years to come.

Not everyone buys into the throwaway world or has to always run with
the supposedly latest and greatest.

Of course, since you're goal wasn't really to comment intelligently on
the thread, but instead just to flame Jobst, I guess that's
irrelevant.

jim beam is a salesman in the `real world.'


gosh, the terrible things bored people will say when having a slow day.
only 3,418,427 unread web pages between you and being able to not be a
schmuck in public.

John Thompson wrote:
On 2008-03-31, Tom Sherman wrote:
John Thompson wrote:
How do you "wear out" a frame? Damage, yes -- either through neglect or
abuse, or what have you. But "wear out?"

Corrosion (metal frames),

I'd file that under "neglect."

fatigue (metal and composite)

Not an issue with a properly designed steel frame, but certainly a
potential issue with aluminum. I'm not aware of composites having
fatigue failures, but I may just be ignorant on that point.

In any bicycle frame, there will be stress raisers that will cause
localized stresses about the fatigue limits (if such a limit exists for
the alloy in question). Typical stress raisers occur at welds and other
joints. Therefore, a steel or titanium/titanium alloy frame might NOT
have as long a fatigue life as aluminium alloy frame made from a
material with a lower endurance limit.

and degradation of epoxy and adhesives (composite).

Disposable frames, then. I'll stick with steel, thank you.

Composites are highly sensitive to means and methods of construction.
The first generation of CFRP frames were typically disposable - latter
quality frames much less so.

Any frame that pushes the limit on how light it can be made is most
likely a "disposable" frame, no matter the material.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful