I wonder if anyone can suggest anything here?

On both bikes (commuter and a rockhopper) the seat post slips. A lot. On the commuter I can loose about 1/2″ in 10 miles and on the rock hopper it seems to drop the same in a mile!

Both use 30.9 seatposts. I have tried replacing the seatposts, its the same. I have shimmed the commuter to 27.2 and tried a 27.2 post. Its the same. I have replaced the quick release clamp on one with a bolty one and no matter how far I torque it the post still slips!

I am using a bit of grease on assembly – should I be putting them in dry perhaps? Its Finish Line BB/hub grease (only one handy in the shed).

I am just under 100kg and I have a fair bit of seat post showing on both bikes.

Help!

All my posts slip with grease too 🙂 Put them in dry.

Try this

that stuff worked for me but it’s pretty expensive, although it goes a long way. drop me an email (thevirgoesataoldotcom) and I’ll put some into a sample bag for you to try and see if it works first.

All my posts slip with grease too

Is this wise? I thought they had to be greased. I did wonder if this was the point of failure though as I have tried everything else!

Will that carbon paste be okay with Alu and whatever seat posts are made of (alu? steel?).

Thanks for the help!

Mine did. Cleaned off the grease & remove them weekly now to keep free. No more slipping…

Cleaned the grease off and still got some slippage this morning on the way to work.

Time to try the fancy compound – would this:
http://www.wiggle.co.uk/p/cycle/7/Finish_Line_Fiber_Grip_Carbon_Fibre_Assembly_Gel_50ml/5360038013/
be the same stuff?

Would it make a difference even though none of the parts are carbon?

Looks like it’d do the trick.

It’s the carbon particles in it that give the extra grip. Doesn’t matter that your post and frame aren’t carbon it’ll still work.

I’ve used it on a Ti frame and alloy post.

Thanks all – problem is now resolved on the commuter with a combination of cleaning the seat post and frame of grease and using the finish line carbon paste stuff. Due to work commitments the mtb has not been out properly but a quick play on the street re-assures me that its probably fixed as well.

My knees would like to say thanks to everyone for thier help here! 🙂

With the Tacx Carbon Assembly Paste what happens if you want to take your seatpost out to adjust or if you’ve bought a new post. The Tacx paste sets doesn’t it?

I dont know. The finish line stuff I bought from wiggle doesnt set. It does however scratch the seatpost up (abrasive compound and all that) but the seat post gets scratched going up and down anyway.

I got a sachet of red stuff with an FSA carbon seat post, which seems to work very well. I think it has plastic bits in it which get squished when you tighten the seat clamp, and it isn’t scratchy. It doesn’t set, and prevents seizing. CRC appear to be selling sachets of the same stuff under the Ritchey brand.

Great tip I picked up from Sheldon Brown’s website is that if you avoid rotating the seatpost when inserting it, then you don’t get scratches.

Frisky – Member

With the Tacx Carbon Assembly Paste what happens if you want to take your seatpost out to adjust or if you’ve bought a new post. The Tacx paste sets doesn’t it?

No it doesn’t.