Seapost sizing & shims

[goo_mason]

I'm still being plagued by the creaking seatpost on my SCR2. It gets temporarily cured (usually) by removing the seatpost and shim, and cleaning the shim up, then regreasing and re-inserting.

I've taped up the slot in the seatpost tube on the frame to stop mucky water getting in when it's wet, but that's not helped.

I'm considering getting a new seatpost that'll do away with the need for a shim. The trouble is, the seatpost diameter marked on the frame is 31.7 (I think, or is it 30.7 ?) and the closest size I can find online is always 31.6. Therefore there's a 1mm difference that'll probably creak even more unless there's a shim.

Anyone fitted a seatpost that's 1mm out without any problems, or did you all have to use a bit of a Coke Can as a thin shim ?

 

[HLaB]

On my old bike I used to have a coke can for a shim, I never had a problem with it.

 

[james_so]

...
I'm considering getting a new seatpost that'll do away with the need for a shim. The trouble is, the seatpost diameter marked on the frame is 31.7 (I think, or is it 30.7 ?) and the closest size I can find online is always 31.6. Therefore there's a 1mm difference that'll probably creak even more unless there's a shim.
...

31.7 mm -> 31.6 mm is 1/10th of a mm, not really very much TBH and would be easily taken up when tightening the clamp, but I'm no expert on such things so may well be wrong

 

[goo_mason]

Did you bend a bit over the top so that it didn't accidentally drop into the seat tube when you were putting it in ?

One more question for anyone to answer - could I wrap electrical tape around the outside of the existing shim to provide a barrier between it and the frame and prevent the metal on metal contact ?