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Carbon Seatposts - Created Equal?
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I am in search of a new seatpost for my rain bike. This sees all manner of duties from CX, gravel, long road rides, etc. Had a Thomson post in it for years that is ready to give up the ghost due from corrosion (long story there). For the purposes of this exercise assume the new post will be carbon.

I'm not out to spend a huge amount of money, and the candidate post needs to be fairly robust and reliable. I know the majority of 'suspension effect' will come from tire pressure but if I am getting a new post I may as well optimize the system. Goals for choosing a carbon post are for ride quality - weight is not really a concern for this bike.

That said, questions are:

- Frame takes a 31.6 post. Any tangible benefits to be gained from shimming down to 27.2 or is this just a pain in the ass waiting to happen?
- Is there tangible benefit from 'flexible designed' seatposts such as the Niner RDO post vs. any other normal carbon post?
- Any differences to be seen from a cheaper carbon post (FSA SL-K for example) vs something exotic (Enve, etc)?
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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What brand/model frame do you have?
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Re: Carbon Seatposts - Created Equal? [jimatbeyond] [ In reply to ]
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'11 Blue Norcross SL.
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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The answers to your question will depend largely on how much seatpost you actually have sticking out of the seat tube. If you run a short seat post you are unlikely to be able to notice the difference between posts. The more seat post that is exposed the more it will flex and therefore the more likely you are to notice difference.

I have a 54 road bike with a 27.2 carbon post that is almost at its limits of being too high. I also have a 56 CX bike with a 31.6 allow post that is nearly slammed. I can just about tell the difference (when riding the same wheel and tire set-up) between the two but its not significant enough that I would pay to switch between the setups.
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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I chose a Ritchey SuperLogic-Carbon post for my gravel bike specifically because it's designed to flex for comfort, and it's performed perfectly from day one. It's a huge difference from my Thomson. It's offered in a 31.6 option.




Your favorite mafia sucks.
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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You may want to consider a post that doesn't require an adapter for non-round rails. It gives you more saddle choices should you decide to change.
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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Shims are just a bad idea. Two interfaces to slip. You need a thicker wall diameter for the same strength,... Stick with the appropriate diameter.

As far as price, there is generally a limited return for your investment. Really inexpensive posts can be a complete waste of the purchase price (no-name stuff on EBay). I would decide how important comfort is an then look at your options. The Thompson posts have always been very nice quality, but I bet they are about as stiff and harsh as you will find.
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Re: Carbon Seatposts - Created Equal? [scott8888] [ In reply to ]
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Good point on the exposed length. It's fairly short for me, probably about 5-6".
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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I did the opposite, went from a carbon post to an aluminum post on my CX bike. The bond between the clamp and the post started to fail, so any time I took a divot, my seat would rotate and I would get a mid race prostate exam... The weight difference was negligible, the comfort difference not noticeable (unless you factor in the comfort advantage of not having mid race prostate exams, in which case +10,000 for the alu post)... the price difference was noticeable. Of all the places on the bike that I would spend the extra money on going carbon, making it light, seatpost isn't one of them...
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Re: Carbon Seatposts - Created Equal? [Trauma] [ In reply to ]
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Large part of my reason for going carbon is to prevent future corrosion issues. My current setup got messy since the anodizing on the post was damaged and it started to grow all kinds of crap and eventually seized in the frame. I was able to get it out after a ton of effort but I don't want to deal with that again. Despite my best efforts to clean the frame I'm sure there is still some sort of chemical funk going on down in there and I'd rather reduce the potential for more problems down the line.
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Re: Carbon Seatposts - Created Equal? [JesseN] [ In reply to ]
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The corrosion and 'freezing' is why I'll never run another alloy post.



- Frame takes a 31.6 post. Any tangible benefits to be gained from shimming down to 27.2 or is this just a pain in the ass waiting to happen?

Shimming down to a 27.2 on one bike worked great for me. No slipping at normal torque. Used carbon paste. The black shim matched the seatpost and clamp, so it's nearly invisible. Was it the actual post or the size that made the difference? I don't know.



- Is there tangible benefit from 'flexible designed' seatposts such as the Niner RDO post vs. any other normal carbon post?

Did you see the BikeRadar test yet? I think you nailed it on tire pressure being more important that the seatpost.



- Any differences to be seen from a cheaper carbon post (FSA SL-K for example) vs something exotic (Enve, etc)?

I can't answer that. My most 'exotic' post that I still use is a 0 offset Easton EC70 that's 8-9 years old now. It just works. I had a FSA K-force break on me about 20mm above the clamp on a road bike in short order. My "cushiest" seatposts were a take off from a Giant Defy and a superlight post from an early Madone. The Madone post has performed admirably on a CX bike. A couple dozen cx races, less than beautiful remounts from a 190 lb rider, and zero slips. I have sure gotten my money's worth out of that one. My lightest and probably least expensive post has gotten beaten up quite a bit and done great. My most expensive post snapped < 1 year on a freaking road bike. That alone leads me towards 'cheaper' posts. I'm curious what other's experiences have been.
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