seatpost slip problems

I have a 27.2mm thomson seatpost in my steel hardtail frame and it just keeps slipping ! I have bought a thomson seat clamp and some carbon paste but that does’nt stop it , it’s driving me mad 🙁 any ideas ?

I have the same, and I’ve snapped a hope clamp doing it up too tight, used carbon paste etc etc.. Does it move a bit side to side with the clamp undone? And does it creak when its done up?
I did stop it slipping by using a seatclamp and some front mech shims on the post for a bit, but that dented the Thomson post! I’ve swapped to a longer post and a nukeproof clamp, but it still creaks and creeps, but much less so.
Next stop (when I finally get around to it!) is to get some 0.1mm steel engineering shim in there. Last try will be to get a 27.4mm Thomson post.
Hope that helps!

yes it does creek , I will see if the post rocks tomorrow maybe a 27.4mm might help or a shim ? Thanks for advise

Try a better clamp? Talc?

Had a similar problem with my Rock Lobster. Its pretty easy to make a shim using a coke can. They are easily cut with a stanley knife. Just use a ruler to get the cut straight and some wet and dry to take off the sharp edges.

The only problem with a shim is it can be a bit of a pain if you take the seatpost out regularly. That’s why I went for a 27.4mm Thomson seatpost in the end which goes in fine with a bit of a wiggle.

I’ve got a redbull can sat on the side waiting to be cut up and had a go with.. Only I get the feeling that it’ll probably be a little thick. Shame they don’t make steel drinks cans any more, or they would be ideal. Next stop is this:
Shim in a can!

I had the same problem – ie. creaking & slipping. For me the carbon assembly paste seems to have fixed it for now, but if not I’m gonna look into a double bolt seat clamp.

There’s two types out there – one is just double the depth of a normal clamp and has two bolts so more of the seat post is gripped – like this.

The other type has one bolt clamping the seat tube as per normal, but another with smaller diameter that directly clamps the exposed seat post – see this[/url].

Haven’t tried either of these yet, and would be interested in the experiences of anyone who has…

I know this sounds daft but when you fitted the Thomson seat clamp did you fit as per instructions the bolt end with the seat tube split (i know thats not its name lol). It makes a difference if only slightly to the clamping force applied, it does “look” a bit wrong though as the shape of the seat clamp looks like it should go the other way.

Worth a go though, i had awful slippage with my steel frame and standard 27.2 post but changed to a Thomson post which was better but still slipped using other seat clamps so bit the bullet and bought a Thomson seat clamp too, all faultless now no slippage at all.

I had a look at them perthmtb. Carboncycles also do one:
here
But nobody does one for 27.2/29.8 which is the common size for steel seattubes.
TBH, I think it’s more of a sizing issue in my case than how hard I can squeeze it. (fnar fnar!) And TBH, I don’t want to buy another Thomson just to get a 27.4 as getting a Ti or carbon 27.2 post in with a thin shim would be much more comfy.

I used the Pace seatpost grease which worked well. But on measuring my thomson post with a digi-caliper it was actually a few thou under 27.2 (from new!). A cheap FSA one was spot on!

Salsa or Chromag seat clamps are all I use now.

Post used to slip in my hardtail with different clamps. I ended up with the previous generation of Hope clamps. The band is narrower than most so I presume it effects more force on the seattube and post for the contact area. Post has never slipped using that.

Check it out! The cheapy-own-brand-redbull-alike can fits! Measured my supposedly 27.2 post to be about 27.0andalittlebit, and my frame to actually be about 27.2andabit, and the can to be 0.1-0.12.
Will have a go on it at the weekend and see if it’s now quiet without hauling on the clamp bolt.