I've found these of limited use. First, they don't seem to be necessary - putting a Presta tube into a rim drilled for Schraeder seems to work fine, at least it has for me every time I've done it, and that's quite a few times now. Second, the grommets seem loathe to remain in place very long, at least for me.
Steve "if it ain't necessary..." Freides
Rick Chasteen wrote:
>
> Ladies and gentlemen:
>
> Does anyone have a source for the rubber grommets which convert Schrader valved rims to Presta?
>
> Rick Chasteen, Kansas City