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  #1  
Old 01-23-2020, 08:44 PM
sailorboy sailorboy is offline
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Opinions on condition of this seatpost please

I recently removed this ritchey superlogic post from a Ti bike that has a thomson post clamp. Not installed by me so I have no idea what spec it was torqued to. There is what I would call a crease in the carbon at the top edge of where the back of the clamp was. No crack that I can see. Thoughts on whether this is trash or could be used again? If we apply medical logic to it, the defect is on the compressive or non-tensile side of the post, so normally that is less problematic for a bone with a stress fracture
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  #2  
Old 01-23-2020, 09:27 PM
rustychisel rustychisel is offline
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DON'T LIKE.

Never seen a seatpost busted through such a thing, but have seen a few steerer tubes fail at very similar pinch points.

Having had a broken seattube (alloy) suppository many years ago I would err on the side of caution and junk this.
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  #3  
Old 01-23-2020, 09:41 PM
HenryA HenryA is offline
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Its done.
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  #4  
Old 01-23-2020, 09:47 PM
Blue Jays Blue Jays is offline
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Post

Years ago I had saddle rails fail on a saddle that had been used a pretty long time.
Dumped me onto the road at (perhaps) 10 mph. I had been doing 40 mph a few minutes earlier.

That experience drove home the fact that bicycle components do have a lifespan.
Now parts that are even remotely "suspect" to me get swapped for new components.

If I am teetering on a decision, I err on the side of safety.
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  #5  
Old 01-23-2020, 10:09 PM
bikinchris bikinchris is offline
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I would never use that unless that crease was well below the clamp.
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  #6  
Old 01-23-2020, 10:20 PM
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false_Aest false_Aest is offline
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I think there is 1 rule about carbon fiber bike parts.

"If you have to post a picture and ask on a forum the part automatically needs to be replaced."
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  #7  
Old 01-23-2020, 10:20 PM
jtakeda jtakeda is offline
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^^+1

If that crease was below the clamp id use.

Maybe make a really fancy BMX post
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  #8  
Old 01-23-2020, 10:29 PM
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shine a light near the damage on the outside while looking down the post. if its cracked or broken the light will shine thru.
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  #9  
Old 01-23-2020, 10:43 PM
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nighthawk nighthawk is offline
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Ride it until it voluntarily becomes a dropper post, then throw it away.
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  #10  
Old 01-23-2020, 11:26 PM
Peter B Peter B is offline
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Cut it into short pieces and use them to protect the seatube during shipping of future bike sales.
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  #11  
Old 01-23-2020, 11:29 PM
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Veloo Veloo is offline
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Reminds me of a guy on our Donut Ride here many years ago. I believe it was on one of those Giant bikes that were the first to adopt the sloping top tube and longer seatposts.
It was an alloy post and I heard the guy scored the post right at the clamp line so as to mark the height.
Don't know how many rides it took but I was told the post broke cleanly right at the score line. I didn't hear any stories about injuries.
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  #12  
Old 01-23-2020, 11:49 PM
Mike Lopez Mike Lopez is offline
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Stick a fork in it...It’s done...

Quote:
Originally Posted by sailorboy View Post
I recently removed this ritchey superlogic post from a Ti bike that has a thomson post clamp. Not installed by me so I have no idea what spec it was torqued to. There is what I would call a crease in the carbon at the top edge of where the back of the clamp was. No crack that I can see. Thoughts on whether this is trash or could be used again? If we apply medical logic to it, the defect is on the compressive or non-tensile side of the post, so normally that is less problematic for a bone with a stress fracture
Don’t think your med logic applies here. Composites do tend to fail in compression, especially when damaged like that. Basically it’s already failed...just hasn’t gone catastrophic yet...
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  #13  
Old 01-24-2020, 12:04 AM
Tony Tony is offline
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I'd ride it. Seen many carbon posts with the same clamp crease and no problems.

My Serotta CIII does similar damage to carbon posts due to poor design. The seat tube extends less than 3/4" above the top tube requiring the seat clamp to be tighten more than what is normally required otherwise it slips. When tightening the seat clamp instead of even pressure being applied around the seatpost only the very top of the seat tube is applying most of the clamping pressure (due to little material above the top tube) causing the top of the seat tube to cut into the post.

Last edited by Tony; 01-24-2020 at 12:52 AM.
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  #14  
Old 01-24-2020, 03:12 AM
sailorboy sailorboy is offline
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Haha, some great answers here, thx all. I will probably just keep it as a spare in case the one that replaced it has an issue. Thx Mike Lopez for the industry expert opinion as well, I guess you know a thing or two bout carbon 😉
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  #15  
Old 01-24-2020, 04:58 AM
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fignon's barber fignon's barber is offline
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The only medical logic I'd apply is "what's your deductible?".
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