[steel515]

Do some valve extenders require special floor pumps or pump adapters?
I notice one does not fit on my performance floor pump. Also how do you choose the "best"?

 

[Mr. Versatile]

Extenders are sometimes needed on aero rims. As long as they're presta valves they should fit fine.

 

[Akirasho]

... most valve extenders are simple pipes that thread unto your standard presta stem... a rare few are designed to accept a valve core on their end (effectively moving said core from tube stem into the extender). Still even rarer are those with their own proprietary valve cores on the end (QBP sells these). All should fit a standard presta head pump (although the QBP extender might be a bit bulky).