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Carbon Seat Rails.

Old 04-14-24, 06:46 PM
  #26  
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Originally Posted by Biker Pete
2-3 nm torque, RXL carbon saddle and seat post, 175 lb rider on pretty even roads.
Obviously not relevant to the thread's original post, since it describes something that obviously did not happen with your saddle; in fact, I can't really see any failure in the photo. Am I missing something? I feel like there must be a crack somewhere that I'm not seeing.

btw, 2-3nm seems like a very low torque for a saddle clamp; is that Bontrager's spec?
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Old 04-14-24, 08:25 PM
  #27  
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Originally Posted by Koyote
Obviously not relevant to the thread's original post, since it describes something that obviously did not happen with your saddle; in fact, I can't really see any failure in the photo. Am I missing something? I feel like there must be a crack somewhere that I'm not seeing.

btw, 2-3nm seems like a very low torque for a saddle clamp; is that Bontrager's spec?
It sounds like you are accusing me of being incapable of breaking something. Well, guilty as charged, but I do have great aspirations.

I read in the instructions to tighten to 4 nm but what Ďfeltí right to me was 2-3 nm. Iím patiently waiting for the cracks to form and the saddle to fall off.
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Old 04-14-24, 08:30 PM
  #28  
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Originally Posted by Biker Pete
It sounds like you are accusing me of being incapable of breaking something. Well, guilty as charged, but I do have great aspirations.

I read in the instructions to tighten to 4 nm but what Ďfeltí right to me was 2-3 nm. Iím patiently waiting for the cracks to form and the saddle to fall off.
Oh, okay, so you're just showing us an example of cf rails that haven't broken. Like almost all of them.

I would torque it to spec, especially since even 4nm isn't much. But you're probably fine.
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Old 04-14-24, 09:31 PM
  #29  
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My carbon railed C13 (technically a 17 in width) has supported my more ample rear for many years and is still going strong. It is installed on a Ritchey Classic post and was done properly with a torque wrench. I do occasionally worry about it and would prefer it to be titanium but it was carbon and works fine. So long as you have the correct clamping mechanism for the saddle (check with the manufacturer) and you torque it all properly and don't ride like a maniac you will be fine.

Carbon is quite a strong resilient material. If it wasn't they wouldn't be using it in all the various critical applications they use it in. I know it is easy to hate on carbon certainly it can fail terribly but so can many materials if treated poorly in some way or another.
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Old 04-14-24, 09:54 PM
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Originally Posted by veganbikes
My carbon railed C13 (technically a 17 in width) has supported my more ample rear for many years ...
If your saddle really is 17 inches wide, you do have an ample rear.
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Old 04-14-24, 10:44 PM
  #31  
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Originally Posted by 79pmooney
The left clamp is what I was asking about in my earlier post. The clamp edge being into the start of the turn of the rails. CF doesn't "flow" at all so the concentrated force at that clamp edge will never dissipate. I asked the OP if this was the case so we could all learn but I suspect the hostile replies drove him off.
I have no idea what this means, and Iím a mechanical engineer (retired).
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Old 04-15-24, 07:18 AM
  #32  
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Originally Posted by tomato coupe
If your saddle really is 17 inches wide, you do have an ample rear.
No it is the designation from Brooks, they have the C13, C15, C17 and C19. If my rear was that big I would have problems and I doubt I could use a carbon railed saddle or probably most any saddle at that point.
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