Originally Posted by
blakcloud
It is best to find a bar that has 31.8 diameter. The Postino is 25.4 so you need the shim to bring your stem down to size to fit the bar. It can be done but I would buy something that you need a shim for. My personal favorite bar of all time is the FSA Metropolis. I have three pair in my parts for future projects.
The Postino is 25.4 because Velo Orange uses quill stems, but you can still find threadless stems in 25.4 without needing a shim. There is an XLC 25.4 stem on Amazon for less than $12:
Amazon.com : XLC Comp Stem, 1-1/8", 110mm x 10, 25.4, Black : Bike Stems And Parts : Sports & Outdoors