Your Touring load will make your bike ride smoother because of the mass...

I have a couple bikes with a seat post sizing shim ,, the Inside is 27.2 , the outside in your case would be 30.8. 1.8mm radial difference .

Id go* for a Cane Creek Thudbuster seatpost rather than expect any great comfort gains from your metal to carbon change
of seatposts ..

* In fact I have 2, one of the long travel, and one of the short travel, both 27.2 shim sleeved out to fit in a larger frame ID..


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