Saddle Rail Failures

1) yes
2) It doesn't matter. Nothing is more important than saving weight.

-Dion

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

Quoted message said:

Two questions on saddle rails:

1) Are tubular saddle rails more likely to fail than solid rails?

2) Would tubular steel rails be more reliable than solid Ti?

Thanks, Art Harris

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

Quoted message said:

Two questions on saddle rails:

1) Are tubular saddle rails more likely to fail than solid rails?

2) Would tubular steel rails be more reliable than solid Ti?

That leaves too many variables, like what kind of steel, how thick and how well made (uniform)
is the tube?

Generally Ti is far inferior to steel here AEBE, but all else is seldom equal.

Titanium rail failures are common yet steel failures, even among a vastly larger sample with vast
quality differences, are not common.
--
Andrew Muzi yellowjersey.orgyellowjersey.orgOpen ↗ Open every day since 1 April 1971

A Muzi said:

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

Quoted message said:

Two questions on saddle rails:

1) Are tubular saddle rails more likely to fail than solid rails?

2) Would tubular steel rails be more reliable than solid Ti?

That leaves too many variables, like what kind of steel, how thick and how well made (uniform) is
the tube?

Generally Ti is far inferior to steel here AEBE, but all else is seldom equal.

Titanium rail failures are common yet steel failures, even among a vastly larger sample with vast
quality differences, are not common.

I second that.

Here in my office, I've got a broken titanium saddle rail. When the time comes to explain metal
fagigue, I pass it around. Nice classic example, with pretty "beach marks."

--
Frank Krygowski [email hidden]

Dion Dock said:

1) yes
2) It doesn't matter. Nothing is more important than saving weight.

Then why, I wonder, bother with that heavy nasty old saddle at all? Just leave it off entirely, and
think of the grams saved. ;-)

"A Muzi" <[email hidden]> wrote

Quoted message said:

Quoted message said:

Two questions on saddle rails:

1) Are tubular saddle rails more likely to fail than solid rails?

2) Would tubular steel rails be more reliable than solid Ti?

That leaves too many variables, like what kind of steel, how thick and how well made (uniform) is
the tube?

Generally Ti is far inferior to steel here AEBE, but all else is seldom equal.

Titanium rail failures are common yet steel failures, even among a vastly larger sample with vast
quality differences, are not common.

What's the failure mode? A bend, kink, or something catastrophic?

"Richard Ney" wrote:

Art Harris said:

Quoted message said:

Quoted message said:

Two questions on saddle rails:

1) Are tubular saddle rails more likely to fail than solid rails?

2) Would tubular steel rails be more reliable than solid Ti?

A. Muzi said:

Quoted message said:

That leaves too many variables, like what kind of steel, how thick and

how

Quoted message said:

Quoted message said:

well made (uniform) is the tube?

Generally Ti is far inferior to steel here AEBE, but all else is seldom equal.

Titanium rail failures are common yet steel failures, even among a

vastly

Quoted message said:

Quoted message said:

larger sample with vast quality differences, are not common.

What's the failure mode? A bend, kink, or something catastrophic?

Shear failure. The reason for my question is that most current saddles are not available with solid
steel rails. I'm looking for the next strongest type. It gets confusing when you start seeing terms
like Vanadium and Manganese.

A booklet that came with my Rolls Classic saddle shows the labeling that Selle San Marco uses. They
use "C" for steel, "M" for Cr-Mo (not manganese), and "T" for titanium. Since Cr-Mo IS steel this is
very confusing. I THINK they use "M" to mean tubular Cr-Mo, and "C" to mean solid steel.

I had a hollow Manganese rail fail once, so I would definitely avoid that. I'm trying to determine
the relative strength of hollow Cr-Mo vs. solid Ti since those seem to be the most available types.

Art Harris

It seems to me that all the saddle rail failures I've seen are usually due to the saddle being too
far back (as in, all the way) on the rails and/or abuse.

Robin Hubert

Quoted message said:

Quoted message said:

Quoted message said:

Two questions on saddle rails:
1) Are tubular saddle rails more likely to fail than solid rails?
2) Would tubular steel rails be more reliable than solid Ti?

<[email hidden]> wrote

Quoted message said:

Quoted message said:

That leaves too many variables, like what kind of steel, how thick and

how

Quoted message said:

Quoted message said:

well made (uniform) is the tube? Generally Ti is far inferior to steel here AEBE, but all else
is seldom equal. Titanium rail failures are common yet steel failures, even among a

vastly

Quoted message said:

Quoted message said:

larger sample with vast quality differences, are not common.

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

Quoted message said:

What's the failure mode? A bend, kink, or something catastrophic?

A rail just snaps, directly behind the clamp..

--
Andrew Muzi yellowjersey.orgyellowjersey.orgOpen ↗ Open every day since 1 April 1971

Richard Ney said:

What's the failure mode? A bend, kink, or something catastrophic?

Again, for this one it was fatigue in bending, directly behind the clamp. That means a small crack
formed at a high-stress area, gradually worked its way through the solid rail, and the last little
bit hanging on snapped in two on a bump. It's catastrophic.

The owner stopped, picked up the pieces, and rode home standing.

--
Frank Krygowski [email hidden]

Frank Krygowski said:

Again, for this one it was fatigue in bending, directly behind the clamp. That means a small crack
formed at a high-stress area, gradually worked its way through the solid rail, and the last little
bit hanging on snapped in two on a bump. It's catastrophic.

The owner stopped, picked up the pieces, and rode home standing.

On a group ride I was on, one of the riders broke a rail. He was able to position the broken part
inside the seat post clamp and finish the ride sitting.

Art Harris

Art Harris said:

"Richard Ney" wrote:
A. Muzi wrote:

Quoted message said:

Quoted message said:

Quoted message said:

Titanium rail failures are common yet steel failures, even among a vastly larger sample with
vast quality differences, are not common.

What's the failure mode? A bend, kink, or something catastrophic?

Quoted message said:

Shear failure. The reason for my question is that most current saddles are not available with
solid steel rails. I'm looking for the next strongest type. It gets confusing when you start
seeing terms like Vanadium and Manganese.

Marketing speak. Vanadium and manganese are alloying elements in steel (ever buy a "chrome vanadium"
screwdriver?). For example, Reynolds 531 is manganese-molybdenum steel (as opposed to Cr-Mo which is
chromium-molybdenum). I have a Selle Italia Sphere with "FeC alloy" rails. Duh, every decent steel
has iron and carbon in it.

Quoted message said:

A booklet that came with my Rolls Classic saddle shows the labeling that Selle San Marco uses.
They use "C" for steel, "M" for Cr-Mo (not manganese), and "T" for titanium. Since Cr-Mo IS steel
this is very confusing. I THINK they use "M" to mean tubular Cr-Mo, and "C" to mean solid steel.

As with bikes, Cr-Mo probably indicates stronger than generic steel, but then they can make the
tubing walls thinner. I don't know that the "C" ones are solid - solid steel rails would be
rather heavy.

Quoted message said:

I had a hollow Manganese rail fail once, so I would definitely avoid that. I'm trying to
determine the relative strength of hollow Cr-Mo vs. solid Ti since those seem to be the most
available types.

I think you can assume that reasonable steels will be stronger than Ti but what you don't know is
the relative quality of design/manufacture. Anything can fail once. Did it really just shear right
off, no bending first? Could there have been a stress riser from the seatpost clamp?

I hear from this thread that Ti rail failures are common. That's a bit worrisome. Any common
features among the failures (mountain bikes, large riders, poorly designed seatpost clamps, seat all
the way back on the rails)?

Benjamin Weiner said:

Duh, every decent steel has iron and carbon in it.

So do all the indecent steels!

--
Frank Krygowski [email hidden]

Quoted message said:

I hear from this thread that Ti rail failures are common. That's a bit worrisome. Any common
features among the failures (mountain bikes, large riders, poorly designed seatpost clamps, seat
all the way back on the rails)?

I'm 140lbs. Bent an 8mm solid steel rail during a MTB race on a BMX saddle. Somewhat of a harsh
crash that gave me a bruise on my bum for a couple days afterwards. It sits on a 20 or 30-degree
slope to the side now.

Phil, Squid-in-Training

Harris said:

"Richard Ney" wrote:
A. Muzi wrote:

Quoted message said:

Quoted message said:

Quoted message said:

Titanium rail failures are common yet steel failures, even among a vastly larger sample with
vast quality differences, are not common.

What's the failure mode? A bend, kink, or something catastrophic?

Quoted message said:

Shear failure. The reason for my question is that most current saddles are not available with
solid steel rails. I'm looking for the next strongest type. It gets confusing when you start
seeing terms like Vanadium and Manganese.

Marketing speak. Vanadium and manganese are alloying elements in steel (ever buy a "chrome vanadium"
screwdriver?). For example, Reynolds 531 is manganese-molybdenum steel (as opposed to Cr-Mo which is
chromium-molybedenum). I have a Selle Italia here with "FeC alloy" rails. Duh, every decent steel
has iron and carbon in it.

Quoted message said:

A booklet that came with my Rolls Classic saddle shows the labeling that Selle San Marco uses.
They use "C" for steel, "M" for Cr-Mo (not manganese), and "T" for titanium. Since Cr-Mo IS steel
this is very confusing. I THINK they use "M" to mean tubular Cr-Mo, and "C" to mean solid steel.

Cr-Mo is just one type of steel, stronger than generic. I don't know that the "C" ones are solid.

Quoted message said:

I had a hollow Manganese rail fail once, so I would definitely avoid that. I'm trying to
determine the relative strength of hollow Cr-Mo vs. solid Ti since those seem to be the most
available types.

I think you can assume that reasonable steels will be stronger than Ti but what you don't know is
the relative quality of manufacture. Anything can fail once. Did it really just shear right off, no
bending first? Could there have been a stress riser from the seatpost clamp?

Andrew Muzi said Ti rail failures are common. Izzat so? That's a bit worrisome. Any common features
among the failures (mountain bikes, large riders, poorly designed seatpost clamps, seat all the way
back on the rails)?

Phil said:

Quoted message said:

I hear from this thread that Ti rail failures are common. That's a bit worrisome. Any common
features among the failures (mountain bikes, large riders, poorly designed seatpost clamps, seat
all the way back on the rails)?

I'm 140lbs. Bent an 8mm solid steel rail during a MTB race on a BMX saddle. Somewhat of a harsh
crash that gave me a bruise on my bum for a couple days afterwards. It sits on a 20 or 30-degree
slope to the side now.

Phil, Squid-in-Training

Let me get this straight: your bum now sits on a 20 or 30-degree slope to the side now? Um, wow.

Sam