Slipping seat post

[Manks]

Hi All

I have an aluminium framed MTB hard tail which I have had for years and just started using again. However when I ride it the seat post creeps lower and lower.

The clamp is as tight as I can get it.

The post used to be lightly greased but the grease has turned to thick gack. I intend to clean the lot up and lube the clamp. But any other thoughts appreciated.

[Rocksteadyeddie]

Does the frame have a small slit down the back of it to allow if to "clamp" the seat pin? If so make sure it's clear of gunk. You shouldn't really need to grease a seat pin either.

[Manks]

Rocksteadyeddie said:

Does the frame have a small slit down the back of it to allow if to "clamp" the seat pin? If so make sure it's clear of gunk. You shouldn't really need to grease a seat pin either.

Yes it does.

Going to try a good clean up and lubing the clamp so I can get it tighter.

[itsnotarace]

Roughen up the seatpost and inside the seat tube with coarse sandpaper and pop a tiny bit of copper slip on to help prevent it seizing

[b2hbm]

Is the clamp cracked ? Not as daft as it sounds, I had one crack just by the bolt a few years back with similar symptoms.

You're lucky though, usually the problem with bikes that are left awhile is that you can't shift the seat pin without damaging either the pin or frame !

[Manks]

b2hbm said:

Is the clamp cracked ? Not as daft as it sounds, I had one crack just by the bolt a few years back with similar symptoms.

You're lucky though, usually the problem with bikes that are left awhile is that you can't shift the seat pin without damaging either the pin or frame !

Don't know. I will have a closer look later.

[Flippin' Kipper]

Get some carbon paste - problem solved.

http://www.wiggle.co.uk/p/cycle/7/Morgan_Blue_Carb...

[Manks]

Flippin' Kipper said:

Get some carbon paste - problem solved.

http://www.wiggle.co.uk/p/cycle/7/Morgan_Blue_Carb...

Neither the bike nor post is carbon.

[Flippin' Kipper]

Manks said:

Flippin' Kipper said:

Get some carbon paste - problem solved.

http://www.wiggle.co.uk/p/cycle/7/Morgan_Blue_Carb...

Neither the bike nor post is carbon.

Does not matter, the paste is because you cannot exert enough force with a clamp on a carbon post to stop it slipping without potentially damaging it, you pop a bit of this on and it allows the frame to grip the post with less pressure. It will woke fine with non carbon bits though.

Edited by Flippin' Kipper on Sunday 17th October 19:38

[Manks]

Flippin' Kipper said:

Manks said:

Flippin' Kipper said:

Get some carbon paste - problem solved.

http://www.wiggle.co.uk/p/cycle/7/Morgan_Blue_Carb...

Neither the bike nor post is carbon.

Does not matter, the paste is because you cannot exert enough force with a clamp on a carbon post to stop it slipping without potentially damaging it, you pop a bit of this on and it allows the frame to grip the post with less pressure. It will woke fine with non carbon bits though.

Edited by Flippin' Kipper on Sunday 17th October 19:38

Oh OK thanks. Good tip.

[shalmaneser]

Rocksteadyeddie said:

Does the frame have a small slit down the back of it to allow if to "clamp" the seat pin? If so make sure it's clear of gunk. You shouldn't really need to grease a seat pin either.

Definitely grease the seatpost. Will prevent it seizing.

[Parrot of Doom]

Quick release seatpost fastener?

It may have been overtightened in the past and isn't clamping properly.