🔧 40mm Presta Tubeless Valve Stem - Pair for Enhanced SEO Review

Easy to install and at least as long as they work properly, these valves were fitted to wide rims for 2.8" tires using Gorilla Tape to tape the rims for tubeless conversion to seal. No leaks or clogs yet; but it's only been a week so I can't comment on long term experiences with them yet.

The valve leaks around the base as several other reviews have said. I spent hours trying to figure out the problem, thought the leak through the spoke nipples was being caused by a tape leak, but concluded it was the valves. Adjusted and added sealant several times but nothing will stop those valves from leaking. Don't waste your money and time buying them!

I've been through a lot of valve stems in my time with tubeless tires. This is by far the best construction I've seen - a bit more solid than other brands I've used. They also have removable cores, which is very important for those of us who want to add sealant without removing the tire bead. I'll see if they have a 60mm version for use with more aero rims.

Should have read all the reviews. As with some other reviewers, after installing my new tires and wheels and applying sealant through a drilled hole in the rim, these valves leak. They don't seal properly. Big mess to reinstall my tubeless tires with old Stan valves which solved the problem. Buying them to save a few bucks is a mistake. Stick to well-known brand components. I'm not at all sure with all the positive reviews about Revain. Read and believe the negative reviews!

Couldn't get them to the valve seal on my rims (Alex CXD4s) with Donnelley/Clement USH tires. Tried o-rings inside and out. Literally spent hours and hours on these valves. Should have just paid the extra $7-8 for a Stan valve as I eventually gave up and switched to an old pair of Stan valves and got better results straight away (there were still some minor valve seal issues but I did not regluing it after using these stems, and I suspect this is partly due to these things blowing up the valve…

I think these 40mm presta valves are perfect for my mountain bike. I tried other 46mm valves and they were too long. I like that these valves are made of brass rather than aluminum due to the added strength of the threads. I use a rubber grommet instead of an o-ring because I feel it provides a more complete seal when compressed. I really like the shape of the lock nut on these valves because it holds the sleeve in place well. I also like the silver color of these valves instead of the brass…

I used a pair of 40mm tubeless Presta i72 valve stems to convert my MTB to tubeless. The rims I converted were not tubeless and had adapters with Schrader to Presta valve holes. These adapters are like "rings" that fit into holes that match the size of Schrader valves and are slotted to allow for contraction/expansion during installation. This separation creates massive air leakage. These valves, along with two layers of Stan's rim tape and Stan's NoTube sealant, successfully sealed and turned…