Back in 2019 I replaced my outdoor bike (a Roubaix) that had Roval CLX 40 wheels with a Tarmac with CLX 50s. As the Roubaix is used almost exclusively in my stationery trainer set up, I don’t have use for several spare tubes with 48mm valves. [The CLX50s require 60mm valves]. The 48mm valves on the tubes (Specialized Turbo Tubes) do not have removable cores. So my questions are these:
Do valve extenders work reliably on valves with non-removable cores?
If so, I’m looking for good ones 20mm length. Any recommended brands/links? (The few Amazon ones I have seen of this length have mediocre ratings).
I’ve used them on and off for many years w/o much problem. Make sure you take a pair of needle nose pliers and fully lock the presta nut in the open position. If not, each time you screw on the extender it will (can) close (turn) the nut so that the valve is shut.
I have some from Zipp, Continental and I think Vittoria. They all seem to work about the same. A little teflon tape helps seal between the extender and the valve.
I’ve always had too many headaches with extenders. I could only get them to work reliably with teflon tape on the threads. I was also concerned about getting stuck on the road somewhere while changing a flat and trying to transfer an extender to a spare tube.
I just buy the tubes with a long stem. Cheap insurance.
After a fair bit of research and helpful input from those who responded, I ultimately decided on the path you suggest. On my “to do” list is to find a fellow cyclist who can use the shorter valve stems.
Don’t forget the spare tire with a long valve plus an extra or two. I one time got stuck because my extender wasn’t compatible with the spare in my seat pack (no threads!).