Originally Posted by TejanoTrackie

I've found this alternative to also work well >>> http://www.unicycle.uk.com/shop/shop...?catalogid=779 The little rubber grommet can be found in hardware stores and you install it on the outside hole of a typical double section (boxed) clincher rim. The grommet pretty much fills in the gap between outside and inside of the rim, so the valve won't push out through the hole when inflated. To prevent the inside hole from cutting the tube, I use 2 layers of rim tape in the area of the hole.