# Carbon Seatposts on a CX bike - yea or nay?



## mdutcher (May 1, 2005)

I am running a Ritchey WCS carbon post on my CX bike. What are the odds of a 150 lb guy breaking it upon a re-mount? Has this occurred with anyone out there? Thoughts, comments, feelings on the subject either good or bad is appreciated.

Thanks!


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## rjb294 (Jun 17, 2005)

mdutcher said:


> I am running a Ritchey WCS carbon post on my CX bike. What are the odds of a 150 lb guy breaking it upon a re-mount? Has this occurred with anyone out there? Thoughts, comments, feelings on the subject either good or bad is appreciated.
> 
> Thanks!


I say if you've got it...use it. Nothin wrong with a little carbon thrown in there.


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## OnTheRivet (Sep 3, 2004)

mdutcher said:


> I am running a Ritchey WCS carbon post on my CX bike. What are the odds of a 150 lb guy breaking it upon a re-mount? Has this occurred with anyone out there? Thoughts, comments, feelings on the subject either good or bad is appreciated.
> 
> Thanks!


Hard to say how likely that seat post is to break but when light durable aluminum posts are available is it a risk you want to take?


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## atpjunkie (Mar 23, 2002)

*well how many*

CF posts are designed with people jumping onto them 2x every 7 minutes?

what's the downside? Carbon shards in your taint

I say go for it

some pals of mine mfr a CF cx bike
they both use Thompsom Alu posts


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## EricN (Apr 9, 2009)

I watched a guy bust his carbon post remounting in a race last season.

Aluminum for me, thanks.


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## endure26 (Jan 27, 2005)

I've broken two carbon posts - they basically folded on me. I weigh more than you do at 180. A friend and fellow racer broke the carbon post that came on his Specialized Tricross mid-race last season and he's all of 150 soaking wet. His post snapped completely off and looked like a tribal spear - luckily it didn't get his undersides.

I've learned my lesson and run nothing but Thomson. Ironically, I broke one of my Thomson seat clamp bolts right after a cx race last season -- on my cool down. Ordered up a replacement and a spare. Seat posts take a lot of abuse in cross.


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## saird (Aug 19, 2008)

If you're breaking seatposts carbon or otherwise you're doing it wrong. Very very wrong.


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## Vegancx (Jan 22, 2004)

saird said:


> If you're breaking seatposts carbon or otherwise you're doing it wrong. Very very wrong.


I agree part of the problem is sometimes technique - jumping on the bike instead of stepping on the bike. 

Still, carbon posts aren't designed to take the kinds of forces we put on them in 'cross. That's why even folks with very good technique break carbon posts.


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## the mayor (Jul 8, 2004)

I've used USE carbon posts for years....one is from 1997..the others are 2001 and 2006. Never had a problem with any of them. I do about 20-30 races a years...and weigh between 160 to 210(currently 160).
One thing you can not do is clamp them in some bike stands...or over tighten the clamp collar.
your mileage may vary.


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## rkj__ (Mar 21, 2007)

I'd suggest aluminum.


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## dankilling (Aug 27, 2002)

Scary- Thompson only for my fat arse, please.


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## pretender (Sep 18, 2007)

It all depends on whether the seatpost is built from (a) carbon fiber, the material, or (b) carbon fiber, the marketing gimmick used to sell overpriced underbuilt components to weight weenies.


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## rkj__ (Mar 21, 2007)

pretender said:


> It all depends on whether the seatpost is built from (a) carbon fiber, the material, or (b) carbon fiber, the marketing gimmick used to sell overpriced underbuilt components to weight weenies.


A carbon fiber seatpost can definitely be made stronger than an aluminum one, of comparable weight, but the problem is they often try to make them too darn light.


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## MeLikeyBikey (Aug 14, 2008)

If its all you got, then use it. If you have a choice (old alu SP lying around) use IT. The benefits of a carbon SP are weight and strength but if it breaks the potential harm is...ugh, unimaginable...ouch. The difference in weight is what like 50-100 grams? If that is the difference between coming 1st or 2nd then do it, if its the difference between 70th and 71th I would consider other options for improvement.


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## single1x1 (Mar 26, 2005)

make sure to use the torq wrench if you do use carbon, many I've seen broken break at the collar, likely over torqed. I have used a carbon easton ct2 post for one season, but got a thomson w/set back after that, I had started to hear a little creaking, (on the easton) and had it at max extention cause it was a road lengh post- and still just a little shorter then my usual SP height.


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## endure26 (Jan 27, 2005)

Nope - the two that folded on my were on my road bike. No jumping involved. One was a Use and the other an early Easton. At the time I was about 175 lbs. I'm guessing, but suspect they both fell victim to overtorquing - trying to get the seat collar on my Litespeed to hold the carbon post without slipping. After my road experience, I've never used a carbon post for cx.


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## morganfletcher (Oct 18, 2004)

Nay

Seen way too many broken ones.

Think about the sudden force of a remount.

Nay

Morgan


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## Doctor Who (Feb 22, 2005)

After seeing a teammate crack two Ritchey WCS cf seatposts in races last year, I was further convinced of aluminum's better qualities.


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## FondriestFan (May 19, 2005)

Using a carbon post for cyclocross is just a decision between risking anal wreckage and saving a few grams vs. taint safety and a bit of extra weight.

I mean, really.


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## Andrea138 (Mar 10, 2008)

The used bike I just bought has a carbon seatpost and stem... I'm gonna give it a shot- I'll post photos of any disasters


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## atpjunkie (Mar 23, 2002)

*I hear for winter of 2010*

Man-Ginas will be all the rave
you'll be ahead of the trend

is there anyone out there advertising their CF posts as 'designed for the rigors of cx racing"?
if not, someone should, I see a market

no other form of cycling puts a post to the loads a rider jumping on and off indices

just do the wrap / weave sio it can handle fairly constant side/diagonal loads


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## Guest (Sep 8, 2009)

the specialied tri cross comes with a carbon post


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## Samhain (Jun 14, 2008)

Thomson is the only seatpost I would use for anything offroad related.


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## alembical (May 21, 2004)

I like and use the Thompson stuff too, but another post/saddle combination that I think deserves more merit and popularity for cross is the SDG I-Beam stuff. I have been using one on a cross bike for a while now and really liking it. No rails to bend or brake. Just another option to the Thompson.


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## colinr (Nov 20, 2006)

Carbon posts for cross is the worst risk/reward equation ever. 

Seriously what is the benefit of this carbon post you have?

Another fun way to break them is tightening your seatpost collar past the torque spec . "Why would I do that?" you ask. Because otherwise the post can slip when you remount.

My girlfriend has a carbon post (sponsorship deal, she wouldn't have paid for it) and the "tight enough to not slip but still within the torque spec" sweet spot is pretty small. Huge pain in the ass.


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## Kram (Jan 28, 2004)

dankilling said:


> Scary- Thompson only for my fat arse, please.


Ditto. Get back to us on how the free azz-reaming goes......


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## the mayor (Jul 8, 2004)

I guess I have been doing it wrong for all these years.
How did I ever survive?


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## nrspeed (Jan 28, 2005)

Carbon post for me this year- 









For alloy- I would recommend the old Campagnolo ti or Shimano alloy posts (depending on your group). I cant stand the look and adjustment on Thompson posts and BTW- Thompson posts break too.


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## Andrea138 (Mar 10, 2008)

nrspeed said:


> BTW- Thompson posts break too.


No wai!!!!!











I think that anything will break if it's abused too much


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## atpjunkie (Mar 23, 2002)

*we know*



superfly-2008 said:


> the specialied tri cross comes with a carbon post


and I assume most of us have seen one break where the Zertz insert is

should we do a head count

1) me


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## bikermancam (Jun 12, 2007)

aluminum has a fatigue life, carbon does not.
Keep perfecting the technique.:thumbsup:


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## Kuna (Oct 14, 2002)

*Love this topic*

Any seatpost can break, I wonder how all the Mountain bikers use carbon seatposts and are ok? Weird. A carbon post can be heavier then aluminum and some aluminum is weaker then carbon. A good brand that is properly (torqued correctly) set up (for your weight and style) and you will be fine. Those that say their seatpost is taking a beating from their mounts need to work on their mounts - it's a smooth slide onto the saddle not the Lone Ranger mounting his horse jumping from the second story of the saloon.


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## m_s (Nov 20, 2007)

I know of even fewer people using carbon posts for mountain biking than cross. 

Anyways, I'm not so worried about the strength of the kalloy carbon post I used to use (it was kinda porky for a carbon post anyways) but as someone else said, there was an annoyingly fine point of torque where it wasn't supposedly overstressed or slipping. After two races having my seat slide down to the top tube I was pretty much done with it.


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## mdutcher (May 1, 2005)

*They have spoken...*

Sounds like the vast majority say Thomson or some other aluminum one.

And yes, someone did point out that the Tricross comes with a carbon post. Mine did.

Run what you have....

...I will give mine a try for the few races that I have planned. If something happens, than I will shove in something else... I do have a Moots Ti post that I could use.

Thanks for the input.


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