# List of seat posts for use with carbon rails



## raganwald (Mar 1, 2011)

I bought a saddle with fat carbon rails, and a Hylix carbon seat post. The clamp doe snot fit :-( I did a little searching, and there are threads here discussing the issue, but no specific list of lightweight posts that will accommodate a saddle with the fatter carbon rails (7x9?). I foun done mention of Bontrager xxx, but of course there must be others.

If you are using a carbon railed saddle, can you reply here with the brand and model of seat post you are using? In addition to helping me find a new post, the thread may prove useful for others with the same question. Of course, if I missed a thread with an explicit list of compatible posts, links would be appreciated!

Thanks...

p.s. I am on 31.6, if that helps.


----------



## GTR2ebike (May 3, 2010)

Thomson works with 7x9
Syntace Hiflex works with 7x9

Most top/bottom clamping posts will work with 7x rails, it's the side clamping posts that has issues.


----------



## sfer1 (Feb 22, 2009)

Thomson Elite and Masterpiece
Syntace P6 Alu, Carbon and HiFlex Carbon
Easton EC90
Ritchey WCS 2-bolt
MCFK


----------



## a2gtinut (May 23, 2007)

sfer1 said:


> Thomson Elite and Masterpiece
> Syntace P6 Alu, Carbon and HiFlex Carbon
> Easton EC90
> Ritchey WCS 2-bolt
> MCFK


MCFK is ~300 Euro :crazy:


----------



## sfer1 (Feb 22, 2009)

a2gtinut said:


> MCFK is ~300 Euro :crazy:


241,60 € (non-EU customers are exempt from VAT)


----------



## B.Trimble (Oct 26, 2011)

Smud


----------



## a2gtinut (May 23, 2007)

sfer1 said:


> 241,60 € (non-EU customers are exempt from VAT)


I forgot about it since I buy toys during my trips to Germany.


----------



## StolltheMusic (Dec 25, 2011)

Enve/Edge seat posts.


----------



## tonloc08 (Mar 13, 2007)

Crank brothers cobalt 11 with adaptor, 157g @ 350mm


----------



## whybotherme (Sep 12, 2008)

any of the "Woodman" style posts with a Smud lower cradle!

Allison runs a New Ultimate Evo on her Sworks HT with a Smud lower cradle and carbon railed Romin saddle.

i prefer the Thompson posts, tried a Smud lower cradle and it broke under my fat butt (150lbs)


----------



## GTR2ebike (May 3, 2010)

whybotherme said:


> any of the "Woodman" style posts with a Smud lower cradle!
> 
> Allison runs a New Ultimate Evo on her Sworks HT with a Smud lower cradle and carbon railed Romin saddle.
> 
> i prefer the Thompson posts, tried a Smud lower cradle and it broke under my fat butt (150lbs)


Don't you mean 148lbs lol


----------



## 1SPD (Apr 25, 2010)

Well, I have been using a KCNC post with no problems! Granted I did swap out the lower cradle for a Thompson one and then to a Smud Carbon version. I have an SLR saddle with the thick rails as you described. Been riding this style of clamp for over 1.5 yrs now without any problems. 

My weight when I got the post/seat combo was 185 though I am now down to about 172 (since Jan). My 350mm x 27.2 KCNC post is 139g stock. With the carbon smud cradle the weight is the same. Add another 8g to that for a stock Thompson cradle.

In any case, with that said, you can use just about any post with that style of mount provided you add a little support to the rails (ie. Thompson lower cradle)


----------



## 1SPD (Apr 25, 2010)

Sorry, I noticed above that someone snapped a Smud craddle at 150 lbs. Odd because they are rated for up to 180 lbs. At least that is what he told me when we were going back and forth on the subject (I also ordered a seat from him as well). As I mentioned, I have been on mine for over 1.5 years now with no problems and I'm still some 20 lbs heavier than the guy that broke his. Perhaps it is just hit or mis there.???


----------



## rockyuphill (Nov 28, 2004)

I expect that some of these boutique manufacturers aren't leaving enough allowance for dynamic loads. A 150 pound person could put the same force on a saddle/seatpost as a 200 pound person in certain riding conditions, like a G-out or a drop impact.


----------



## 1SPD (Apr 25, 2010)

No no, I totally agree! I was just saying that apparently I have been fortunate enough to not have any problems with mine. I will add that I carry a Thompson craddle in my tool bag in the event it ever breaks though! Nothing like riding home without a seat!


----------



## Tiffster (Jan 30, 2008)

Eaton EC90 works perfectly with carbon rails.

31.6x400mm with ti bolts 191 grams for reference.


----------



## lucifer (Sep 27, 2004)

Fizik cyrano


----------



## panzer07 (Jun 18, 2008)

Lynsky TI post also fits carbon rails


----------



## ibogey99 (Sep 23, 2009)

+1 for Easton EC90. Mounted a Spec Phenom Pro to one today.


----------



## purdyboy (Nov 15, 2005)

1SPD said:


> I will add that I carry a Thompson craddle in my tool bag in the event it ever breaks though! Nothing like riding home without a seat!


That is kinda ironic.

(Not trolling or trying to be snarky, so please accept my comment in the light heart-ed manner that is intended...)


----------



## raganwald (Mar 1, 2011)

purdyboy said:


> That is kinda ironic.
> 
> (Not trolling or trying to be snarky, so please accept my comment in the light heart-ed manner that is intended...)


Just carry one of these:






Bergmönch - Hiking uphill Wheeling downhill from Thomas Kaiser on Vimeo

In all seriousness, sometimes a lighter bike and heavier pack is a reasonable trade-off. The debate heads over into platform vs. clipless territory, but searching for bottles vs. CamelBak will reveal that a number of people think you get a better experience with a light bike you can flick under your body, while others believe you get a better experience with as little weight on your body as possible.

Shrug!


----------



## mmike84 (May 2, 2016)

This is an old thread but I am posting what Thomson told me about using their seat posts with carbon railed seats:

Question- I have a Thompson Elite dropper post on my yeti that is about a year old. I bought a carbon WTB seat with carbon rails. The rails are oval as opposed round on my old seat. My local bike mechanic said I cannot use the Elite clamping mechanism with carbon rails. I looked around online but could not find anything definitive. Can you confirm if they are compatible with each other or if you have a different clamp for carbon seat rails?

Answer- https://www.bikethomson.com/product/seatpost-clampset-7x7-rail/

You would need the oversize 7 x 10 clampset available at the link above

Raymond Gonzalez

Thomson Bike Products, Inc
L.H. Thomson Company, Inc
7800 NE Industrial Blvd
Macon, GA 31216
USA
www.bikethomson.com


----------



## scant (Jan 5, 2004)

bontrager XXX with the oversize rail adapters.


----------

