SM Titanium Saddle Rail FailureS

[bobscott]

Anyone else out there had trouble with San Marco titanium saddle rails? I just broke the second set of titanium saddle rails on Regal saddles. I weigh 170 lbs so I don't think it is excess weight. They are solid not tubular titanium and they fail catestrophically with a large pop. One saddle was about 6 months old (replaced by distributor), the other 6 or 7 years. I am careful not to nick them/ add any stress risers during installation.
I want a bit more durability than this and am thinking of avoiding ti rails. Don't know how hard that is going to be these days.
Is this a real problem or my freak-out after two failures?

[Birddog]

I've had one for some time time now with no problems. I'd guess maybe 5,000 miles or more on it. Is it possible that the clamp is causing the problem? Do they break near the clamp or elsewhere? My weight varies between 170 and 180lbs

Birddog

[OldDog]

Long time Regal user. Never a problem. Posts being used are old style American Classic and recent years Record and Chorus, 3 different bikes I switch between.

[swoop]

check your seatpost clamp and don't overtighten. i've never ever had an issue..

[stevep]

no controversy.
steel rails are much more durable.
unless you are really light sub 140
you might be better w/ steel
weight saving is negligible. durability is better.
busted rail= bad ride home.

[bobscott]

Thanks for the input.
I am using a Dura Ace/Easton post (7400?). It did break next to the front of the post clamp; saddle was as far back as it will go, the right place for me. I had recently put a new saddle body on the rails and did reset-up the post. As I remember, the rail was fine on inspection but I didn't look very closely for hairline cracks. I did torque it down well but that shouldn't be a problem in my view as the rail clamp ends are chamfered.
Appears to be my bad luck on these two.

[Grant McLean]

Double check your next one with a torque wrench, but broken ti rails are
very common. Our shop gets dozens every year, from all brands, from
Selle Italia, Fizik, San Marco, there's no real pattern.

g

[Frustration]

Maybe look at getting a post with more set back too...


sLamming your saddle all the way back puts stress right on the bend. That's not good regardless of the rail type.

[harlond]

I outweigh you by 30 lbs minimum and I've ridden a titanium Rolls for 10 years without incident.

But I suppose that will all change now.

[Johnnyg]

Anyone else out there had trouble with San Marco titanium saddle rails? I just broke the second set of titanium saddle rails on Regal saddles. I weigh 170 lbs so I don't think it is excess weight. They are solid not tubular titanium and they fail catestrophically with a large pop. One saddle was about 6 months old (replaced by distributor), the other 6 or 7 years. I am careful not to nick them/ add any stress risers during installation.
I want a bit more durability than this and am thinking of avoiding ti rails. Don't know how hard that is going to be these days.
Is this a real problem or my freak-out after two failures?
Bobscott Get a set back post so your weight will be more evenly distributed on the rails. Good luck, johnnyG

[bobscott]

Let me say, defensively, that the post's setback was sufficient for the rails to be completely cradled by the seat post clamp. The rails were not resting on the side of the clamp in any way.

On another note, I wonder if anyone has tried San Marcos Rever Profil with the Sandvick hollow stainless steel rails? It has a jivey nano name which I hadn't seen applied to metals to date but is certainly currently all the rage.

[RPS]

I think that the recommendations above are based on the fact that if you move the saddle all the way back, your weight acts on a longer moment arm and puts a lot more bending stresses on the rails. From a durability standpoint, it would be best to support the rails near their center.

[bobscott]

Thanks for the comment RPS as it brings to light another puzzing aspect of the rails failure.

Since: The saddle was all the way back on the rails
One would expect: The rail to break at the back of the seat post clamp since there is more saddle over hang and a longer lever arm acting on the rail there.

But, as my second post states, in both cases the rail broke at the front of the clamp. In addition, I NEVER sit on the nose of the saddle.

My only explanation (but not a good one) would be that the over hang in the rear of the saddle allowed more twisting or tortional force on the rail and this lead to the failure.

[RPS]

You make a good point; and without looking at how the saddle and post clamp are made it's hard to know why it would break in front of the clamp.

Personally I'd replace the seat post before installing another saddle.

[swoop]

you ever see a pipe cutter at work?