MBP Alloy Bicycle Tube Presta Valve Extenders (2 Pack) 20mm-60mm

First off, there is a slew of 1-star reviews here from dolts who don't understand the product they're buying. No, you can't screw it onto your valve core - because that's not how (most) valve extenders work!If you know what you're buying, the product works well. No leaks in my case, even without grease or PTFE tape.When ordering, be aware that the advertised size is for the exposed portion of the extender only. The overall length including threaded portion is longer than the nominal size, contrary to what the product description claims. See picture: The Zipp extender is nominally 27mm compared to the nominal 30mm of the MBP; the actual difference in length is almost 12mm.Lastly, be aware that you're not getting 4 extenders in different sizes as pictured; what you get is 2 that are the same length.

I was pretty worried when I read half the negative reviews on here, but once I got the valves I'm guessing that a lot of people simply weren't sure how to install them. You have to take out the valve core and replace it by threading the narrow end of the extender with the rubber gasket on it. Then you re-install the valve core at the tip and hey presta, you're all set. If at first they don't seem to be threading correctly, you might be doing it wrong. Haven't had them long enough to see if they retain air perfectly, but initial impressions were good.

These are useless unless you have Teflon tape or plumbers putty to stop air leaks. Once those are added though, it is a great product. One thing I failed to do the first couple times seating the tube is to have these babies tightened absolutely all of the way on.

These valve extenders fit well. I have not had leak issues with almost a year of use and without using thread tape. The poor reviews seem to be from users that do not understand that these extenders work with removable core tubes. You need to remove the valve core from your tube, install the extender, and then re-install the valve core into the extender.

I purchased a pack of 30 mm and a pack of 40 mm and out of the 4 only 1 didn’t have a slight leak

Threads on extension adapter to fine for some presta inner tube valve stems.

Always go with these Removable valve core extenders. Without modification The other types without valve core relocation, make it difficult to get properly measure air pressure and nearly impossible to access the valve core in deep section wheels.

Worked good. You do need to put teflon tape on them to get them to seal.