Seatpost on my P7 keeps sliding down no matter how tightly its done up. It only slides down to a certain point which is about 70mm below required height, there is a metal shim in there already and its well within the max height.

Was I reading on here the other week about using a coke can?? Any other advice appreciated, thanks

Yup, I’ve used a coke can shim, works fine

Is it just a case of cutting a piece of aluminium section fromt the can and curving it to fit in ther frame. Im assuming you’ve got to bend the top to form a lip so it doesnt fall in to the bike frame when taking seatpost out?

Is your seatpost the correct size? Even a tiny bit out can cause problems. They used to be 29.6mm.

talcum powder/warranty

Sib, sounds like you have it, BUT, I was having a similar problem, I use a quick release seatclamp, and weird as it sounds a bit of grease A, on the seatpost and B, lube up the cam on the quick release, it stopped mine slipping, I think the clamps work better and can clamp harder when they are lubed up…

Cut a long piece of beercan so that you can wrap it around the seatpost when inserting it into the frame. It may slip upwards, so make it deep, as well. Say 8×8 cm?

If its just slipping but there is no free play I doubt a beer can shim will fit in.

Check the sizing of the set tube and the seatpost. Sand them to get more grip?

I replaced the shitty QR clamp which came with my P7, but the Hope clamp I now use still slips very slightly, enough for me having to adjust every other “big” ride. I might try the coke can trick myself…

Oh, and have you modified your rear dropout with the third bolt? This was a “known” issue on the 2008 and later frames which I didnt know about till I noticed my brake mount wobbling when braking.

Thanks for all your advice…..will be going home to get out the talc, some lube, some grease and a beer can – sounds like a dirty afternoon ahead!!

stupid question are you sure you have the correct seatpost? what post have you got? ive got a thomson.

i have a 2008 model and mine hasn’t slipped at all i do tighten the clamp to the verge of snapping though which probably is not a good idea.

Mine does it too. If you don’t faff with the height of your seat on rides then buy a non-quick release clamp and then tighten it as hard as you can and then a little bit more.

Probably a dumb idea but it is working well for me.

waihiboy – picked it up new from lbs about 8 weeks ago so I’m assuming correct seat post but will check. I’m taking it back for its first free service v soon when problem will hopefully be solved but I just want to know what’s wrong with it. Like you I’m tightening the clamp sooooooo much – has started to bend the lever already, not happy!!

I’m liking the idea from tinsy of bit grease on seat post and lube on clamp – never had any problems the first few weeks so I’m thinking grease and lube might have dried by now if it was on there originally ………..but it still shouldn’t happen, there shouldn’t be a need to use grease and lube.

It wont hurt to have a bit of lube on it all, the post is also less liable to pick up on the inside of the frame and get scratched up too.. Without a shaddow of doubt the clamps can do their thing so much easier with a bit of grease on the cam, you will be supprised how much easier it is to click into the locked position. Let us know how you get on.

I’ve had a slipping Thomson on my Inbred (I’m a bit of a big biffer) and managed to solve it using a Salsa clamp (they seem a tad wider than some) and some Tacx carbon assembly paste. The paste is supposed to have micro-spheres or something in it which aids grip (hence you can use less torque on carbon posts). I think that it’s also meant to help reduce galling (I’d normally use copper grease for this purpose if the post didn’t slip).

try a post .2mm bigger? if you can fit a coke can in the gap its wayyyyy to loose surely?

The clearance between my frame and post is tight enough to hold the post even before the clamp’s done up, as the frame was powdercoated and i didnt quite mask up to the end.

I’ve used the aluminium can shim before, but then discovered this stuff….

RC005 Carbon Composite Shield
A small tub of blue goo to you, but a life changing synthetic suspension of friction increasing polymer globes as far as your sinking seatpost is concerned. A thin smear is enough to reduce clamping torque on carbon or alloy seatposts by up to 30%, minimising the risk of crush or cracking damage and keeping your seat height right for ride after ride.

Specification 80g
100% fully synthetic. 30% reduction in
clamping torque

It’s about £7 a tub, but you don’t need much, so a tub should last years. It’s suberb stuff, now use it on both my bikes (alloy) seatposts and it’s eliminated any seatpost slippage – and you don’t have to overtighten the seatpost clamp/qr.

oops..forgot to mention the grease is made by Pace; it’s on their website under ‘Fluidworx’

Has anyone else tried the RC005? Will it be ok on the 2010 P7 Frame?