sliding seatpost

[Chuckles1981]

anyone have any tips advice on fixing a sliding seatpost???
when i go over hard bump it happens

[LuckyPierre]

road v off-road?
quick release v bolt?
carbon v alloy?

[Chuckles1981]

its an MTB on clamps and its alloy

[tallywhacker]

blue loctite between the seatpost and seat tube before tightening. Leave it to dry overnight.

[Shard]

If it's 1-2mm too small try wrapping a cut coke can (cylinder bit) around the bit being clamped, that should keep it in place.

Shard

[winona_rider]

don't tell anyone i told you this...but some packing tape once or twice around does the trick. BUT! you gotta clean it out and replace the tape every 2 or 3 weeks depending on how often you ride.
in saying this i STRESS i got sick of this pretty quick and bought a seat post 0.2 mm thicker for 10 bucks and it has been freakin awsm. werd

[alchemist]

its an MTB on clamps and its alloy

Not a Scott is it?

[LuckyPierre]

The big tip underlying the responses so far is - check that you've got the right size seat post - 0.2mm makes a big difference, especially for quick release clamps.

[twowheels]

Could be the contoured plastic shim/washer that the QR clamps onto has split, like my plastic one did. Kept retightening the thing before I realised what had happened.

I replaced mine with a metal shim/washer from an old brake assembly, the little part that make sthe brake sit "flat" on the brake bridge or fork ... hasn't slipped since.