Originally Posted by HillRider

Your quill stem is made for a 1-1/8" steerer (ID= 25.4 mm, OD = 28.6 mm) which is apparently what's on the bike. Your steerer adapter is made for a 1" steerer (ID = 22.2 mm, OD = 25.4 mm) and it's the wrong one. You need to get an adapter made for a 1-1/8" steerer.

Nashbar offer them in both sizes: http://www.nashbar.com/bikes/Product...8_10000_202442 The product description under "Features" described the differences.