# Do I lube a carbon seatpost mated to carbon frame? how about alum post to carb frame?



## sqwk77 (Sep 13, 2010)

I have one bike that is a carbon frame with a carbon seatpost. My LBS did not lube it in any way.

I have another carbon bike with an aluminum seatpost. That different LBS slathered grease all over the post. 

Seems like neither setup should need any type of lube whatsoever as neither should really seize.

I understand there is some type of "carbon Paste" which I believe is gritty grease for grip. What is its use?

Whats the word....lube or no?
Thanks!


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## cxwrench (Nov 9, 2004)

carbon assembly paste...it lubricates, but has 'friction enhancers' that keep carbon parts from slipping. so the post (hopefully) won't get stuck, nor will it slip. i'd stay away from grease, just because the post may slip. if you don't put anything in there and ignore it, it could get stuck.


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## reptilezs (Aug 21, 2007)

the the al post, grease is fine. for cf you can use grease but it raises the issue of slippage. when it slips people want to tighten the clamp more and then the post gets crushed.


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## frdfandc (Nov 27, 2007)

Here is what I do when assembling bikes. I've used this method for quite a while and seems to work fine.

Carbon on carbon - usually dry. If its a very tight fit, then a light coating of grease. If it slips, carbon paste.

Alloy on carbon - Always use grease.


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## XR4Ti (Jul 8, 2008)

Carbon paste for both.


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## LOUISSSSS (Dec 14, 2009)

frdfandc said:


> Here is what I do when assembling bikes. I've used this method for quite a while and seems to work fine.
> 
> Carbon on carbon - usually dry. If its a very tight fit, then a light coating of grease. If it slips, carbon paste.
> 
> Alloy on carbon - Always use grease.


i use carbon paste whenever any carbon tubing is involved, carbon/carbon, carbon/aluminum. for alu/alu i use grease. My current is a thomson post + carbon frame, i used carbon paste.
on my mtb is a FSA Carbon post + alu frame, i used carbon paste also.

with carbon paste on any carbon tubing i dont need to clamp down as tight.


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## Ibashii (Oct 23, 2002)

I started using the carbon paste on my FSA seatpost//CF frame combo because it's a tight fit, and I have to take it off to travel. It makes less scary noises while taking off and on, which makes me feel better. It's a small investment, why not do it?

OTOH, if the fit isn't too tight and you're torquing to spec and keeping everything really clean and you take it off from time to time and it doesn't bother you, it's all good.:wink:


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## Kontact (Apr 1, 2011)

I don't see the rationale for* ever *putting two tight fitting parts together without something to prevent seizing. Even carbon on carbon can stick horribly if sports drink gets in there. Between carbon paste, grease and anti-seize (ti prep), there is always something that works.


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## Special Eyes (Feb 2, 2011)

You should not lube a seat post unless it is a C to C joint, then use carbon paste.


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## Kerry Irons (Feb 25, 2002)

*Why not?*



Special Eyes said:


> You should not lube a seat post unless it is a C to C joint, then use carbon paste.


Can you back this up in any way? I've been doing it with posts of every composition in frames of every composition for many years. No slipping, no sticking/seizing/damage to the seat post. I'm trying to figure out why what I have been doing is so wrong.


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## Kontact (Apr 1, 2011)

Special Eyes said:


> You should not lube a seat post unless it is a C to C joint, then use carbon paste.


Either you wrote this wrong, or are seriously mis-informed. An aluminum post in a steel frame will become permanent in no time at all.


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## Special Eyes (Feb 2, 2011)

I was just reading the instructions that come with some seat posts. Comment not based on experience. Seemed to make sense to me, but apparently not a big deal.


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## Blue CheeseHead (Jul 14, 2008)

XR4Ti said:


> Carbon paste for both.


+1 

Carbon assembly paste works just as well for aluminum to carbon. I use it on aluminum seat post to CF seat tube and aluminum stem to CF bars. It reduces required torque, stops slipping and stops creaks & squeeks. Both FSA and Finish Line make it.


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## Kontact (Apr 1, 2011)

Special Eyes said:


> I was just reading the instructions that come with some seat posts. Comment not based on experience. Seemed to make sense to me, but apparently not a big deal.


Which ones?


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## lewdvig (Oct 4, 2004)

Carbon post in my carbon frame grase seems to have fused the post into the frame after 2 weeks. 

I would seriously stay away from any grease that does not explicitly say it is carbon safe.


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## Kontact (Apr 1, 2011)

lewdvig said:


> Carbon post in my carbon frame grase seems to have fused the post into the frame after 2 weeks.
> 
> I would seriously stay away from any grease that does not explicitly say it is carbon safe.


No, it didn't. There is no such thing as "carbon safe" grease. Carbon epoxy composites are very chemically neutral. Greasing carbon headset races and BBs is normal practice. Your advice is based on a bad guess from a single occurance, not fact.

Your post is stuck, but the grease didn't cause that. Not enough grease might have.


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## lewdvig (Oct 4, 2004)

Kontact said:


> No, it didn't. There is no such thing as "carbon safe" grease. Carbon epoxy composites are very chemically neutral. Greasing carbon headset races and BBs is normal practice. Your advice is based on a bad guess from a single occurance, not fact.
> 
> Your post is stuck, but the grease didn't cause that. Not enough grease might have.


Yup, you are right. I think it might have been too much grease as the tolerances on the TCR Advanced and Aero post are super tight. There was a crap load of the stuff in there.

After an ungodly amount of force it came out.

I read Sheldon Brown's instructions and got er done.


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## Ibashii (Oct 23, 2002)

lewdvig said:


> Yup, you are right. I think it might have been too much grease as the tolerances on the TCR Advanced and Aero post are super tight. There was a crap load of the stuff in there.
> 
> After an ungodly amount of force it came out.
> 
> *I read Sheldon Brown's instructions and got er done.*


Ahh, if only everyone just started with Sheldon's website...

RIP Sheldon: your influence will outlast you by decades.


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## erict (Apr 4, 2011)

Good reading on what "carbon assembly paste" is, why it works and what it's for on the  competitivecyclist.com site.

For my new bike build I used grease, carbon assembly paste and anti-seize compound as needed per manufacturer recommendations. (Yep, I actually read the instructions)


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