Every bike shop I've been to advocates using carbon specific paste for lubricating carbon seat tubes/bikes. They swear up and down that regular grease is 'bad' for carbon. But every bike manufacturer or parts manufacturer I've talked to on the subject say there is no way it can hurt the material. I tend to agree with the latter.

This was addressed by Zinn through VeloNews in the last few years. He solicited the feedback of many in the industry but the general consensus (IIRC) is that you can use it if you like and there should be no ill effect.

Carbon assembly paste works very well at the job it is designed to do FWIW.

Real world experience: my seat post has been mated to my bike fram with garage grease since May, 2008, with no problem.

I thought the purpose of the paste was to enhance the friction between post and tube, rather than decrease it, as I suppose grease would do...?

I'm sure carbon paste works great, but grease is much more likely to be in my toolbox/garage.

It was my understanding that the carbon paste contained particles that help prevent slippage. The epoxy that holds your carbon fiber fabric together is extremely resistant to solvents, so you are correct that regular grease won't harm anything.

[Written while Phantoj was posting]

I've only cracked one carbon frame using grease on the carbon seatpost. With that said, no way in hell I will ever use grease on a carbon seatpost in a carbon frame again.

How did it crack?

Never could get it to quit slipping after I wiped the grease off as much as possible, cracked it from over tightening. It was my Fuji Team Issue.

Used to have seatpost slippage with grease. Switched to paste and viola! no slippage.

Very, Very wrong.

Epoxy is soluble in many solvents; ketones, alkyl halides, alkenes, etc... one key reason why one should be careful choosing something like finger nail polish to "touch-up" the clear coat.

I do all of my own wrenching but don't own a carbon post. But if I did I'm pretty sure I would either get the paste or have lbs do it for me. I'm guessing this is low frequency maintenance so why not get the right stuff in lieu of having issues or even cracking your nice frame?

"I thought the purpose of the paste was to enhance the friction between post and tube, rather than decrease it, as I suppose grease would do"

If you want to change out your seat post, or change the height of your seat post because of a new saddle, or new pedals, you'd want to be able to loosen the seat post.

I don't want to argue with you, but properly cured epoxies are very solvent-resistant. I work in the composites industry.

The paste will not make the seatpost seize in the seat tube, but it will prevent it from slipping.

True. However, ordinary grease won't make a seat post seize, either. That a special formulation is needed to keep a seat post and frame safe from each other is a way to sell expensive grease.

Grease isn't "bad" for a carbon seatpost/frame. But carbon paste is good to use. Reduces slippage and decreases the amount of force needed to clamp it. Look at what happened with LowCel's bike. Don't mean to single you out, it's just a good example. There's a good chance that carbon assembly paste would've kept his post from slipping and he may not have cracked the frame due to constant tightening. I'll always use carbon paste on mine. I'll always suggest other do too. Whether or not they listen is another thing.

I agree that ordinary grease won't cause the seatpost to seize, but carbon grease was designed to do more than that. The fact that it costs more is a combination of the formulation and the relatively small market for the product compared with typical white grease. This isn't some marketing ploy to sell expensive grease to "suckers". Unless there are those out there who have replaced their regular grease with carbon grease because they think it weighs less. Now that would be funny!

I dunno about you guys but I sure do enjoy having to torque my carbon seatpost less than max torque since the carbon pastes reduce the required clamping torque by up to 30%.

The idea is to increase clamping friction to prevent slipping, not to prevent seizing.

This is really a simple thing you guys. Don't make it harder than it has to be.
Carbon on carbon you use carbon paste. If you use grease it won't hurt anything, it will just slip more. The paste increases friction so you don't crack your frame by overtorquing the clamp.
Carbon on Al you use grease to prevent corrosion of the Al.

Carbon Assembly paste contains grit particles, which bite into the otherwise smooth and slick resin of the frame and seatpost, increasing friction. Grease contains no grit - or it wouldn't be very good at it's job. One is ment to increase friction, the other to reduce friction. They are not the same thing, and not interchangeable. Not if you like your saddle staying in place, anyway.

I see I clearly stand corrected, I did not realize you were a professional.

BTW: pray tell what company are you employed by, what is your job with this company... no particular reason.

First off carbon paste is not a lube.
Carbon parts will not seize to other materials which is the main reason you use to lube up your seat post.
The use of carbon paste is to aid in adding friction to carbon parts which allows you to tighten the bolts to proper torque and not have parts slip and the need to over tighten, the added friction keeps parts from slipping.
I'd suggest using it for any carbon parts you need to tighten and keep in place.
I might add why even think of using grease on carbon when carbon paste is designed for it?

My employer does not encourage us to make that kind of information public. If we met in person and were having a conversation, I'd have no problem telling you, but not on a public forum. Even if that weren't the policy, it keeps me from getting spammed by people based on where I work.

By the way, there are solvents out there that attack fully cross-linked epoxy, but they are pretty nasty to work with and aren't generally available at the neighborhood hardware store. Most bike-related greases and adhesives can be easily broken down with citrus-based products anyway, so there is really no reason to even use aggressive solvents.

Take care.

It's not just it's got grit in it. The paste I use, Tacx dynamic assembly compund I think it's called, seems to dry out after application rather than staying ummm greasy. I'd imagine this is exactly what it's designed to do, make insertion easy, then between the grit and the drying, create more friction than just having the naked carbon.

It's always why when I make adjustments, I'll remove the post wipe it down, re-apply assembly compound and refit.