# Specialized Carbon Seat Post Question...



## roadworthy (Nov 11, 2011)

Putting together my new Roubaix frameset which comes with a Specialized carbon seat post. I am usually a big fan of 2 bolt micro adjustable posts but this post has merit _IF_ the saddle will not lose its tilt adjustment as I ride. I guess we will see. Would like to ask those that have the single lateral allen bolt Specialized post as it comes on many Specialized bikes...particularly those riders that are a bit heavier...I weigh 185#...any problem keeping your saddle at the set tilt? I tried an experiment when test fitting my new bike and went with relatively low allen bolt torque and sure enough the saddle rotated rearward when pedaling on the bike.

I found the Specialized PDF for the post and please find below the spec's for not only saddle bolt torque..but seat collar torque.
Perhaps if ramping up clamp torque the saddle will stay in place even with hard riding.
The bolt torque spec is 120 in-lbs i.e. 10 ft-lbs which is a fair amount of torque with a small allen wrench if not using a torque wrench.

Please share your experiences with the Specialized post if you would. A keeper?...will it stay in place with suitable torque...or did you struggle with keeping the saddle in place and therefore went with a 2 bolt post?

Last question pertains to the post in the seat tube itself. Do any of you use carbon paste on the seat post? If not, any problem with post slippage or creaking? I am wondering whether best practice is nothing between seat post and seat tube ID?...as there is no call out for carbon paste on the PDF.

Thanks for sharing your experience


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## PJ352 (Dec 5, 2007)

I'll preface my input with...
1) I weigh ~140 lbs.
2) I don't use a torque wrench.

My experiences with this post are quite the opposite of yours. Out of the box, tilt was difficult to set (because of binding), so I disassembled it, cleaned, re-greased, reassembled and that seemed to minimize the problem.

That aside, I think yours is just a case of not applying enough torque to the bolt, so I suggest resetting tilt and re-tightening, applying slightly more torque. The only caveat is that if you're using a saddle with CF rails, make sure your post has the appropriate clamps, otherwise you run the risk of cracking the rails.

Re: the seat tube/ post interface, I apply nothing. Before assembling, I clean the ID of the tube and OD of the post with denatured alcohol, then wipe both clean. Only if you experience slipping would I suggest applying carbon assembly paste, and (IIRC) Spec recommends the same, but you can double check that.

Re: the use of a torque wrench; there are some here that would argue the point, but I've been working on bikes (complete tear downs/ rebuilds) since the early 90's - and CF since '08. I've never suffered a mechanical incident or damaged any part assembling/ tightening only by feel, but have read a number of posts where members have done so when using torque wrenches. As someone here once stated, my torque wrench is in my wrist. IMO/E, assuming a level of aptitude, going by feel yields good results. Conversely, in the absence of aptitude, no tool will save a user.


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## willstylez (Sep 15, 2011)

Long story short, the Pave carbon post came with my 2011 Tarmac Expert SL3.....and it worked flawlessly. I weigh in at 200lbs.


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## roadworthy (Nov 11, 2011)

Thanks guys. Just wanted to take inventory and get a collective opinion about the Specialized seatpost. PJ...thanks for your in depth comments as always...you being a student of these bikes and cycling in general which I appreciate...kind of advice I was seeking. Quite right...by intent, I applied low torque to the bolt to see if the saddle would rotate and stands to reason that it does. That joint works purely off compression with no indexing of serrations or detents common to other single bolt clamps...many of which slip or are not micro adjustable. Where the saddle is positioned on the rails matters in addition to rider weight as well...in terms of torque on that rotory joint. PJ...I run a Ti railed Toupe on this bike...or will rather...what I have mounted. I try to avoid carbon railed saddles personally but not an end all...would ride one if I came across one for a decent price...just prefer hollow Ti for rails.
As to a torque wrench...we are pretty much in the same camp. I rarely use one on a bicycle as well...have a pretty well calibrated hand with years of wrenching...don't generally use one on even carbon bikes with carbon bars, seatpost etc. I will ramp up the torque...again 10 ft-lbs is quite a bit for a small L shaped allen wrench and will also run the post dry in the seat tube...wiping with alcohol as you suggested which I too typically do...no carbon paste.
Thanks again.
PS: I figured that the post was excellent as it comes from Specialized which in my experience don't make a bad product across the board.


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## PJ352 (Dec 5, 2007)

roadworthy said:


> Where the saddle is positioned on the rails matters in addition to rider weight as well...in terms of torque on that rotory joint.


I agree. That's why I included my weight. 



roadworthy said:


> PS: I figured that the post was excellent as it comes from Specialized which in my experience don't make a bad product across the board.


I think it's a very well made post, but I prefer the 2-bolt designs.


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## Rugergundog (Apr 2, 2011)

Ive used that post for a few years without a problem. Tis on me i don't use a torque wrench either. The new design is a bit different and solves many of your issues.


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## roadworthy (Nov 11, 2011)

Just to update....I have about 100 miles on my new Roubaix. Would be a lot more but weather has started to act more like winter here.  The post is working nicely now that I've amped up the torque. I broke my basic rule of bike building and broke out the torque wrench. 10 ft-lbs seems to keep the saddle in place. The post has a fair amount of compliance as well. I am starting to like it.


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## jnbrown (Dec 9, 2009)

Had the same problem with this post on rear of my tandem.
Tried using carbon paste which was a bad idea as it became stuck.
Finally cleaned the mating surfaces and did not put anything on them.
Used a torque wrench and have not a problem since.


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## roadworthy (Nov 11, 2011)

I am just not used to putting that much torque into a seat clamp is what it comes down to and therefore why I under torqued it initially. Yeah...I wouldn't use anything inside the clamp mechanism as it may diminish friction and cause rotational slippage. Also, per PJ's good advice, I am not applying anything between seat tube and carbon post....I have run carbon paste with Al Thomson posts in carbon seat tubes. One thing I found and word up to others with the Pave post which is common on Specialized road bikes...by the sound of the post clamp when tightening...there is an elastomer within the clamp mechanism that holds the seat in position when this compressible bushing is torqued to spec. What this means is...the bushing which isn't rigid, will likely take a compression set over time. A suggestion I have found is...if you use a torque wrench, check the torque of that bolt from time to time. I find mine loses about 12 inch pounds or so...in about a week's time...or has. I presume over time that bushing will compress to the point where it no longer compresses as readily and will retain a more consistent torque over time. Just a thought. Eventually I will go to a 2 bolt post which Specialized now uses on many of their road bikes and for good reason. I just subscribe to the design of a 2 bolt more than using a single lateral compression joint to retain seat tilt....less compressive stress on seat rails in particular.


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## dcgriz (Feb 13, 2011)

My Roubaix Pro SL3 came with this post and unlike several of you, I am of the opinion that the post leaves a lot to be desired when compared to the 2 bolt designs which is where Specialized has now gravitated to. What I don't like about it: 
A. I find it to be time consuming to do the micro adjustments between fore-aft and tilt. 
B. the cups tend to bind and If the same degree of rotation is not uniformly applied, the saddle rails end up on different horizontal planes causing saddle creaking. Overgreasing the cups is not the answer either as you do not want them to turn too easy
C. It can not reliably accommodate saddle positioning maxed out in any direction as tilt is affected in due time.
D. It can not accommodate carbon rails.

I have about 2000 miles and one year's worth of use on this particular bike, when the time comes I will replace the seat post with a 2-bolt type. Interestingly enough, my 2009 Roubaix Elite was offered in 2009 with a better 2-bolt post clamp than the 1-bolt clamp offered now or offered for my 2011 Pro. I think this appears to be Specialized's approach to maintain a price point as is evident from the deterioration of grouping component choices from what was offered a few years ago to what is offered now for the same model. Not flaming Specialized, I currently own 2 Roubaix and a Rockhopper, and I consider myself to be a fan.

Regarding the comments about wrenching by feel etc. Having worked on engines recreationally all my life and having stripped and sheared more than my fair share of bolts, I do not go near my carbon bike without my trusted torque wrench.

Furthermore, I have found the use of carbon paste desirable to assure that the seat post stays in place over time without exceeding the torque limit.

Unlike some posters, I do find the use of the torque wrench and carbon paste to be beneficial.


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## Stumpy2011 (Aug 1, 2011)

Hi DCGriz.

I have the 2012 Roubaix Expert which comes with the 2 bolts seatpost. 
I also though it was a downgrade compares to previous year model, and even looked into getting the single bolt seatpost but reading your post and others, I guess I'll stay with the current one...
It's simply works - no creaking, no slipping, no carbon paste.
It's a "set it once and forget about it" deal.


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## dcgriz (Feb 13, 2011)

Your Expert appears to have the same post clamp as my 2009 Elite. It's a very basic, minimal setback, post. The clamp is not the best for carbon rails but, on the bright side, is set it and forget it.


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## w-g (Mar 9, 2006)

Late to reply here but I've had no issues with my post. Got the bike in April, riding pretty much every weekend. Set and forget covers it. I've swapped saddles (on my 3rd now) for fit purposes and had no problems tightening the saddle clamp. Or w/ slippage. For reference, this is my first single bolt post, all other bikes are MTBs w. Thomson posts.


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## claywalk (May 7, 2011)

I have been searching for a zero setback post to compliment my SL4. After waiting for months the specialized store finally had the S-Works Pavé NH Carbon Seatpost in stock.

Ordered it. Received it. Installed it this morning with the carbon rail pieces to match my ProLogo seat.

And... it doesn't fit the rails correctly. there is a lot of play when tightened down to the proper torque settings because the carbon rail pieces don't actually conform to the rails themselves and grip them.

I see no real solution here if I want to use the ProLogo seat. the alloy rail pieces are too small... I guess this is a bad match for me.


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## tommyturbo (Jan 24, 2002)

I've used the single bolt S-Works posts for many miles with ti railed saddles. While they were never the easiest to adjust, the posts worked OK overall. Now that I am using a carbon railed Toupe Pro saddle on my S-Works SL3, I switched to the Fizik Cyrano Carbon post with the two bolt clamp. I had tried the Crank Brothers Cobalt 11 single bolt post (with carbon rail adapter) and returned it. The spec called for 12 Nm for the clamp. Not only would I never crank a bolt that tight on a seat rail, the Specialized saddle spec calls for much lower torque.

The Fizik post has setback. I am using a Syntace P6 Hi-Flex zero setback post with a ti railed Toupe on my S-Works Epic 29er. As with the Fizik post, the Syntace has a very carbon rail friendly two bolt clamp with a very long support for the bottom of the saddle rail. Thomson posts also work great with carbon rails.

While I am sure that there are plenty of single bolt posts that will work well with a carbon railed saddle, I've decided I'm sticking with two bolt posts from now on. Two bolt posts are easier to adjust and they are set and forget, at least the posts I have used. Single bolt posts often are lighter, but for me, two bolt posts are worth a few extra grams.


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## claywalk (May 7, 2011)

thanks tom. really good points & you concern about the side torque of 12 NM. I did not even think about that - hopefully I did not do any damage to my Prologo seat. I am sending the s-works post back and found a zero setback Easton post for 50% off today. should work just fine.

That Fizik Cyrano Carbon post looks great btw.


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## tommyturbo (Jan 24, 2002)

Claywalk,
Easton makes good stuff. Yes, the Cyrano is a good looking post, as is the Syntace. But these are bike parts; looks are not important


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## todayilearned (Sep 28, 2011)

I have this seat post on my SL2 and it's such a PITA literally. I weigh 185 lbs.

I just switch over the 2 bolt that came with my SL3 and things are much smoother.


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## jnbrown (Dec 9, 2009)

I used an Easton EC90 zero setback on my SL3.
Got it cheap on Ebay close out.
I have had no problems with it.


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