Topic Title

Advice welcome.

Aluminium seat post in steel or aluminium frame = grease.
Carbon seat post in carbon frame = no grease (someone said talc instead or some proprietory stuff).
Aluminium seat post in carbon frame = ????

Discuss.

No idea. You don't have 2 metals in contact so no anode/cathode issues (carbon fibre isn't conductive AFAIK). If there's any risk of it getting stuck though a smear of grease might be advisable - assuming the grease in question isn't corrosive to carbon. If it does tend to slip - which I'd doubt - then simply wipe clean.

I'm sure someone knows the proper answer!

Carbon - Carbon: no grease. Use hairspray if it slips and a torque wrench to avoid over tightening.

Carbon post in Al frame. No grease. Use hairspray if it slips and a torque wrench to avoid over tightening. Degrease frame if grease has been used before.

ta

Carbon post in Al frame. No grease. Use hairspray if it slips and a torque wrench to avoid over tightening. Degrease frame if grease has been used before.

If you don't have a torque wrench how do you judge?

Carefully! Don't whale away with a long allen key. It's a fine line between tight enough to hold and crushing the seat post. Not that I've ever deformed a carbon seatpost, oh no

I now use one of these:

http://www.parker-international.co.uk/P ... f18b567c74

and do up to 4 nm.

Not that I've ever deformed a carbon seatpost, oh no

And not that I've ever cracked a carbon steerer doing up the stem too tight. And it didn't cost me £200 to put it right.

Came across this whilst idly browsing:

http://www.velonews.com/tech/report/art ... 799.0.html

Different scenarios but it seems that in any event the use of carbon assembly paste/grease is the 'Gold Standard' to prevent seizing. Not sure about slippage but the torque wrench must be the best way to avoid overtightening.