Carbon Assembly Paste

I have an aero carbon seatpost (Planet X) that rocks very slightly in the clamp and ultimately slips earthwards when my arse sits on the saddle attached to it. Planet X rather kindly provide the seatpost with a lovely rough finish about a 10" down from the saddle clamp which would prevent this but unfortunately I'm about 3" away from it. Sooo, does anyone have any Carbon Assembly Paste knocking around that I can use to see if that cures it? I would order it from wherever online and wait for it, but the bike took ages to arrive and I want to try it properly yesterday.

Beer will be forthcoming to the kind soul who smears my post with paste.

I have a tube, you are welcome to pop over and smear your shaft.

You will need the paste and a coke can shim to be safe.

If it rocks in the clamp unweighted and slips when it is weighted then I don't think paste is going to solve your problem - a seatpost that fits will though. FWIW i wouldn't sit on anything carbon that moves or has any play in it at all.

As I understand it, assembly paste is just to stop seizing/minute friction that can damage the parts - not for filling gaps.

I have a tube, you are welcome to pop over and smear your shaft.

Whore.

If it rocks in the clamp unweighted and slips when it is weighted then I don't think paste is going to solve your problem - a seatpost that fits will though. FWIW i wouldn't sit on anything carbon that moves or has any play in it at all.

As I understand it, assembly paste is just to stop seizing/minute friction that can damage the parts - not for filling gaps.

Does sound like a bit too much play.

Assembly paste is designed to add friction. So you can use slightly less torque, when clamping bits onto your carbon parts. Does a good job of preventing bars from twisting in stems, and should help with seatpost slippage too. But yeah, wont compensate for the wrong size post.

I absolutly always use carbon assembly paste, or metal anti-seize. As I hate dry insertions.

If it rocks in the clamp unweighted and slips when it is weighted then I don't think paste is going to solve your problem - a seatpost that fits will though. FWIW i wouldn't sit on anything carbon that moves or has any play in it at all.

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As I understand it, assembly paste is just to stop seizing/minute friction that can damage the parts - not for filling gaps.

It also allows you to lower the pressure applied to carbon parts (indeed all parts) - for example a carbon post without assembly paste might require 12Nm, but with assembly paste it might be only 9Nm (made up figures, but you get the idea).

It also makes removing parts easier, the paste is made from millions of tiny rubber-like balls that compress under pressure increasing grip, but return to a spherical shape when the pressure is removed helping 'roll' the part out.

Edit: beaten to it by Smallfurry.

Ignoring all the above posts, was there was some around Chez Dude a while ago.

Right, back online. The rocking is ultra-minute and you have to put a fuck load of effort into it, as you tend to do when something puzzles you. I emailed Planet X and they suggested simply using hairspray and, you've guessed it, no rocking and no slippage. Time will tell if this is a lasting fix and I'm saving the email for any warranty issues later on.

For now though, thanks for the replies and offers of smearing my post, I may return to take you up on it.

Oh yeah, bloody good guess at 9Nm for the seat post clamp

My P-X TT post slipped. Assembly paste and a bit more torque on the clamp fixed it.
I've read about some people putting bits of wood down the seattube so the post rests on top.

Easier to use sand- then you can shake some out if the saddle is too high.

With wood you would have to saw a bit off- hassle.

I just drilled a hole through mine and pinned it in place.

Oh yeah, bloody good guess at 9Nm for the seat post clamp

Blimey - Thomson suggest 2.8nm for their clamps...

Q – The recommended torque is only 2.8 Nm. Is that enough?
A – Yes. On a 27.2 post in an aluminum frame at 2.8Nm of collar bolt torque it takes 900+ pounds of force to make the seatpost slip.

http://bikethomson.com/collars/

That's alu on alu though.

I was using 6nm and still had a slipping post with an OEM clamp. Bought a Thomson clamp and some carbon paste (alu post in carbon frame) and 2.8nm was enough to hold it...

^creaked like fuck though so had to revert to a carbon post too in the end...

http://thegoldenwrench.blogspot.co.uk/2011/09/tech-bulletin-from-trek-regarding.html

Just read this

Is Carbon Assembly Paste necessary for the interface between stem and steerer tube as that seems to suggest not?

Personally I've only used it if I know I can't get the part to stay put otherwise at the recommended torque (as per my seatpost upthread ^)* or if there could be a catastrophic consequence of any slippage (e.g a smidge on my bar and stem clamp).

It's never occurred to me to use it on a steerer tube because I can't imagine the stem could ever come flying off upwards(!) and it's only likely to move sideways in a crash (which would probably be preferable to snapping off completely or whatever the alternative would be?).

Either way, there is no paste on either of the bikes in my house that have a carbon steerer - one fitted by me and the other by a mechanic...

*I've since discovered that hairspray is just as effective, without scratching anything up...

Anyone have a little bit of this that I can use for a seatpost?

Yessir... although if you've got a slipping post and have access to hairspray this would also probably do the trick.

House full of men and mum that doesn't like chemicals :)
I'll ask my friend if she has any and will try it though :)

Anyone have any advice where I can buy a decent size tub of cardon assembly paste? All I can find online is 100ml for £10.

Thanks.

Couldn't find cheaper when I was looking (I got the Finish Line stuff) - to be fair, 100ml should last an awful long time.

Finish line do a workshop tub of it, pretty pricey though