The last two times I've had new valve stems installed on Mangusta rims the shops commented about the unusual shape and/or size at the stem base. The first shop (sadly now gone!) found some 'unusual' rubber units that would work and I failed to ask for details. The new shop - a Porsche dealer service dept - can't find any solution apparently.
Anybody familiar with this issue, or using rubber stems currently?! (Shop #1's solution shown below) Appreciate your thoughts, Nate