Bar & Stem Fatigue?

Shawn Amir said:

Andrew Lee said:

http://www.sheldonbrown.com/brandt/ Look at the stem in the picture on
the left...

While having Jobst using a similar stem is certainly a comparative
endorsement, it tells me little about the expected service life of the bar
and stem--except that I know he rides many more miles than I do. Jobst,
if you are out there, when do you expect to replace your stem?

He answered this a while back: http://tinyurl.com/3stp2
Steel bars though.

From the archives:

Quoted message said:

By this do you mean the only suitable stem you could buy was for a 1-1/8"
stem? If so, I assume you've ended up with an aluminum stem. A Ritchey
WCS item perchance? Is the reducing sleeve a structurally compromised
design or just aesthetically displeasing?

The best stems are made in 1-1/8" bore and Tom gave me this one with
reducer sleeve because it has one logo right-side-up oriented the way
I prefer. He made these with only one logo as large as the usual two
up/down ones so they would be visible in competition photographs. I
like it the way it is... of course because I designed the the Ritchey
logo and head badge at the time when he first built me a frame.

Quoted message said:

Quoted message said:

This may not be obvious since quill stems were generally safe with a
single bolt failure without the bars falling off even though the
attachment was completely compromised (having no redundancy). That is
not the case with threadless steer tube stems.

Were you not tempted to get your frame builder to make you a stem with a
traditional pinch-bolt fixing at the bar? If your stem must now be
replaced at intervals (being alu) I would have thought a steel item would
have appealed to you as an idea.

What??? Why would I need to replace this stem at intervals? I had
Cinelli single pinch bolt stems that got machined out of the steertube
four or five times over the years. I don't want to go back and why
should I. The tubular threadless stem is far stronger and certainly
more rigid.

Quoted message said:

Of course your stem may well be steel but I've never seen a high quality
steel stem with fixings as you describe and certainly not one built in a
manner other than TIG welding.

Why would you use a steel stem. That's like going back to steel
cranks, solid ones. See stem before and after:

http://www.sheldonbrown.com/br­andt/

Jobst Brandt
[email hidden]­g

Quoted message said:

For the same reasons you still use a steel seatpost and handlebar. Why
does your reliance on steel not extend to the stem?

I don't use a steel seat post and the bars are a matter of failure,
of which I have witnessed enough aluminum bars fail.

Quoted message said:

Quoted message said:

That's like going back to steel cranks, solid ones.

I didn't suggest a solid anything, simply a tubular threadless, brazed
stem made from a high quality steel tubing. Correctly executed, would
tubular steel not be a better material for cranks anyway?

No, that's been tried often enough.

Jobst Brandt
[email hidden]­g

Shawn Amir said:

Andrew Lee said:

http://www.sheldonbrown.com/brandt/ Look at the stem in the picture on
the left...

While having Jobst using a similar stem is certainly a comparative
endorsement, it tells me little about the expected service life of the bar
and stem--except that I know he rides many more miles than I do. Jobst,
if you are out there, when do you expect to replace your stem?

He answered this a while back: http://tinyurl.com/3stp2
Steel bars though.

From the archives:

Quoted message said:

By this do you mean the only suitable stem you could buy was for a 1-1/8"
stem? If so, I assume you've ended up with an aluminum stem. A Ritchey
WCS item perchance? Is the reducing sleeve a structurally compromised
design or just aesthetically displeasing?

The best stems are made in 1-1/8" bore and Tom gave me this one with
reducer sleeve because it has one logo right-side-up oriented the way
I prefer. He made these with only one logo as large as the usual two
up/down ones so they would be visible in competition photographs. I
like it the way it is... of course because I designed the the Ritchey
logo and head badge at the time when he first built me a frame.

Quoted message said:

Quoted message said:

This may not be obvious since quill stems were generally safe with a
single bolt failure without the bars falling off even though the
attachment was completely compromised (having no redundancy). That is
not the case with threadless steer tube stems.

Were you not tempted to get your frame builder to make you a stem with a
traditional pinch-bolt fixing at the bar? If your stem must now be
replaced at intervals (being alu) I would have thought a steel item would
have appealed to you as an idea.

What??? Why would I need to replace this stem at intervals? I had
Cinelli single pinch bolt stems that got machined out of the steertube
four or five times over the years. I don't want to go back and why
should I. The tubular threadless stem is far stronger and certainly
more rigid.

Quoted message said:

Of course your stem may well be steel but I've never seen a high quality
steel stem with fixings as you describe and certainly not one built in a
manner other than TIG welding.

Why would you use a steel stem. That's like going back to steel
cranks, solid ones. See stem before and after:

http://www.sheldonbrown.com/br­andt/

Jobst Brandt
[email hidden]­g

Quoted message said:

For the same reasons you still use a steel seatpost and handlebar. Why
does your reliance on steel not extend to the stem?

I don't use a steel seat post and the bars are a matter of failure,
of which I have witnessed enough aluminum bars fail.

Quoted message said:

Quoted message said:

That's like going back to steel cranks, solid ones.

I didn't suggest a solid anything, simply a tubular threadless, brazed
stem made from a high quality steel tubing. Correctly executed, would
tubular steel not be a better material for cranks anyway?

No, that's been tried often enough.

Jobst Brandt
[email hidden]­g

Per David L. Johnson:

Quoted message said:

or
until a crack begins to appear.

I don't know if this transfers, but all the windsurfing boom failures I've
experiences were from the inside. Corrosion.
--
PeteCresswell

Per David L. Johnson:

Quoted message said:

or
until a crack begins to appear.

I don't know if this transfers, but all the windsurfing boom failures I've
experiences were from the inside. Corrosion.
--
PeteCresswell

(Pete Cresswell) said:

Per David L. Johnson:

Quoted message said:

or
until a crack begins to appear.

I don't know if this transfers, but all the windsurfing boom failures I've
experiences were from the inside. Corrosion.

Dear Pete,

Probably a dumb question, but why is the inside of the boom
more prone to corrosion?

Does the inside of the boom trap sea water that normally
dries off the outside, or concentrate salt through
evaporation?

Carl Fogel

(Pete Cresswell) said:

Per David L. Johnson:

Quoted message said:

or
until a crack begins to appear.

I don't know if this transfers, but all the windsurfing boom failures I've
experiences were from the inside. Corrosion.

Dear Pete,

Probably a dumb question, but why is the inside of the boom
more prone to corrosion?

Does the inside of the boom trap sea water that normally
dries off the outside, or concentrate salt through
evaporation?

Carl Fogel

Shawn Amir said:

Quoted message said:

http://www.sheldonbrown.com/brandt/ Look at the stem in the picture
on the left...

Quoted message said:

While Jobst using a similar stem is certainly a comparative
endorsement, it tells me little about the expected service life of
the component. (Jobst, if you are out there: when do you expect to
replace your stem?)

Quoted message said:

Alas, statements of the form "replace them if you are worried",
while appreciated are also of little help. Being an engineer, I am
too well-acquainted with Murphy and perhaps a little too
paranoid--especially since I have had a face-full of asphalt on a
previous occasion.

Quoted message said:

Let me simply ask, when would you replace a Ritchey WCS bar/stem
combo on your own bike?

So why do you post email that you sent to me and to which already I
responded? Which way do you want it? I won't belabor the subject by
repeating my response here.

[email hidden]

Shawn Amir said:

Quoted message said:

http://www.sheldonbrown.com/brandt/ Look at the stem in the picture
on the left...

Quoted message said:

While Jobst using a similar stem is certainly a comparative
endorsement, it tells me little about the expected service life of
the component. (Jobst, if you are out there: when do you expect to
replace your stem?)

Quoted message said:

Alas, statements of the form "replace them if you are worried",
while appreciated are also of little help. Being an engineer, I am
too well-acquainted with Murphy and perhaps a little too
paranoid--especially since I have had a face-full of asphalt on a
previous occasion.

Quoted message said:

Let me simply ask, when would you replace a Ritchey WCS bar/stem
combo on your own bike?

So why do you post email that you sent to me and to which already I
responded? Which way do you want it? I won't belabor the subject by
repeating my response here.

[email hidden]

Andrew Lee said:

Shawn Amir said:

Andrew Lee wrote:

Quoted message said:

From the archives: ...

Thanks,

[email hidden]

Andrew Lee said:

Shawn Amir said:

Andrew Lee wrote:

Quoted message said:

From the archives: ...

Thanks,

[email hidden]

Per [email hidden]:

Quoted message said:

Probably a dumb question, but why is the inside of the boom
more prone to corrosion?

Does the inside of the boom trap sea water that normally
dries off the outside, or concentrate salt through
evaporation?

My guess would be that it's a combination of never getting rinsed, not being
covered with anything (much of the outside is covered with rubbery foam for
grip), and (in one case) maybe a difference in the coating/anodizing on the
inside vs outside.

The operative word is "guess"....I really don't have a clue and have experienced
only four failures - all of them quite some years ago. All the higher-end
booms made today are of carbon fiber/expoxy.
--
PeteCresswell

Per [email hidden]:

Quoted message said:

Probably a dumb question, but why is the inside of the boom
more prone to corrosion?

Does the inside of the boom trap sea water that normally
dries off the outside, or concentrate salt through
evaporation?

My guess would be that it's a combination of never getting rinsed, not being
covered with anything (much of the outside is covered with rubbery foam for
grip), and (in one case) maybe a difference in the coating/anodizing on the
inside vs outside.

The operative word is "guess"....I really don't have a clue and have experienced
only four failures - all of them quite some years ago. All the higher-end
booms made today are of carbon fiber/expoxy.
--
PeteCresswell

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Andrew Lee said:

Shawn Amir said:

Andrew Lee wrote:

Quoted message said:

From the archives: ...

Thanks,

[email hidden]

My thanks as well, obviously my initial google search was poorly done.

Jobst is obviously of the opinion (from the above and via email) that
properly designed aluminum stems are not subject to fatigue from normal
use... bars being a different matter. Another advised to check the bar/stem
regularly since there are usually some signs (noise, bending, cracks, etc.)
before failure.

The combination of the two statements above gives me some measure of
confidence--wouldn't want to damage the crowns I got after my last face
plant.

Cheers, Shawn

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Andrew Lee said:

Shawn Amir said:

Andrew Lee wrote:

Quoted message said:

From the archives: ...

Thanks,

[email hidden]

My thanks as well, obviously my initial google search was poorly done.

Jobst is obviously of the opinion (from the above and via email) that
properly designed aluminum stems are not subject to fatigue from normal
use... bars being a different matter. Another advised to check the bar/stem
regularly since there are usually some signs (noise, bending, cracks, etc.)
before failure.

The combination of the two statements above gives me some measure of
confidence--wouldn't want to damage the crowns I got after my last face
plant.

Cheers, Shawn

Quoted message said:

On Wed, 30 Mar 2005 20:59:44 -0500, "(Pete Cresswell)"

Quoted message said:

Per David L. Johnson:

Quoted message said:

or
until a crack begins to appear.

I don't know if this transfers, but all the windsurfing boom failures I've
experiences were from the inside. Corrosion.

Quoted message said:

Probably a dumb question, but why is the inside of the boom
more prone to corrosion?
Does the inside of the boom trap sea water that normally
dries off the outside, or concentrate salt through
evaporation?

Probably.
In cars, chronically wet carpets from a windshield leak will
rot floors. (not from the outside in.)

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April,

Shawn Amir said:

I have Ritchey WCS bars and stem, regular not the OS variety. What is the
consensus on fatigue life for these? I have about 10K miles on them so far
with no visible damage, when should I replace them? (I am 195 lb, like to
climb, and stand a lot.)

Cheers, Shawn

If you haven't damaged them in any way, crash, overtighten, no noise,
creaks, etc...just go ride them. They are not known for sudden, fatigue
related failures. i have the same bar on me Bici and I weigh more than you.