UKH

Any suggestions on how I can get my seat post to stop slowly sliding down on my MTB? The clamp is as tight as I can get it, yet on bumpy ground after half an hour of riding it will drop about 3 inches. I still want to be able to raise and lower the seat when I transition from road to technical, but for forest trails and gravel tracks, I want it to stay where it put it!

In reply to supersteve:

What material is the post made of?

In reply to supersteve:

a new clamp fixed that for me - a proper, after-market one, not the crappy OEM thing it came with

In reply to Jim Lancs: The bike is a Lapierre Edge 527, but I can't find anywhere information on the post material. I assume it is the same alloy as the rest of the frame to avoid corrosion. Maybe a new clamp is the answer - will give that a try. 

In reply to supersteve:

You can try carbon gripper paste.  As the name suggests, it's intended for carbon fibre seatposts, but I've used it on an aluminium post that was slipping and it solved the problem.

In reply to supersteve:

I had the same problem on a Boardman MTB seat post, i thoroughly cleaned and degreased the seat post and the seat tube, then used some carbon assembly stuff (https://www.wiggle.co.uk/fenwicks-carbon-assembly-paste) to re-assemble. its been fine ever since. 

Edit: Sam beat me to it!

In reply to Sam W:

Thanks - I will pop to the bike shop at the weekend and give this a go. 

In reply to Sam W:

Yes, the carbon gripper stuff works well on alloy. Think I used the finishline stuff.

In reply to supersteve:

Is it a Quick Release clamp or Allen key?

If QR, try lubricating the camming mechanism in the clamp. Reducing the friction in the clamp means you can exert a greater clamping force on the post. Had this happen on a couple of different qr clamps and this has worked on all of them. 

Also if you are really struggling some carbon fibre assembly paste can really help as mentioned above.

In reply to supersteve:

I’ve had that problem after altering the saddle height. It was tension in the cable from the bars. There should be an adjuster to back the cable off slightly

In reply to supersteve:

Get a dropper and really crank it up tight.