29.4 seatpost in 29.6 shim?

[pelean]

I've found this cheap carbon post on offer which unfortunately is 29,4mm diameter. The seattube on my Principia aluminium bike is 31,6mm. I have'nt been able to find any shim that to fit these exact dimensions, but a 29.6 to 31,8 aluminum shim comes pretty close... The shop says this shim should work. What do you think? As a carbon post is rather fragile I want to make sure that I can both get the shim in the seattube, but also get a secure grip and does'nt damage anything.

-Peter

[CACycling]

The shim should be 1.1mm thick (31.8 - 29.6 = 2.2 & 2.2/2=1.1). You need a shim 1.1mm thick (31.6 - 29.4 = 2.2 & 2.2 / 2 = 1.1). What's not to work?