Putting a Presta stem nut inside the rim? Has anyone ever heard of this? I'm not sure how it happened, but when I went to replace my tire today, I found that I had two stem lock nuts on my valve. One inside the rim and one in the normal place. Not sure if the shop did this for me a awhile back or if I did this absentmindedly last time I changed it. Anyway, it didn't cause any problems and I put at least a few hundred miles on it like that.
Any reason to do that? Thanks!
It is a commonly used quick and dirty fix when you don't have a purpose-built grommet to install in a rim cut for a Schrader valve. It may also not be a terrible idea if, for whatever reason, your Presta-hole rim has a burr or sharp edge and you want to avoid any possibility of problems with that.