Tubeless Valve Stems 40mm Presta Pair - Brass Made with Core Remover Tool, Round Rubber Base with O-Ring for Superior Sealing

Perfectas para mis ruedas

I used a pair of i72 Tubeless 40mm Presta Valve Stems to convert my MTB to tubeless. The rims I converted were not tubeless ready & had schrader to presta valve hole adapters. These adapters are like “collars” that fit into the holes that are sized for schrader valves & have a split in them to allow for compression/expansion when installing. This split allows for a massive air leak. These valves, along w/2 layers of Stan’s rim tape & Stan’s NoTube sealant, successfully sealed & converted my MTB to a tubeless setup.The valves came w/their securing nut & o-rings. These tightened down & seated securely. The cores looked & functioned properly, no issue w/removal, installation, opening or closing. Both my pump & gauge also worked w/the valves properly. I have not had any issues w/them gumming up or sticking because of the sealant. Overall, I am very satisfied w/how these valves have been functioning.Thank you for taking the time to read my review, I hope you found it helpful.

I think these 40mm Presta valves are the perfect length for my MTB. I've tried other valves that were 46mm and they were longer than necessary. I like that these valves are made of brass and not aluminum because of the added durability of the threads. I use a rubber grommet instead of the o-ring because I feel that when it's compressed down it gives a more complete seal. I really like the shape of the locking nut on these valves because it holds the grommet in place nicely. I also like the silver color on these valves instead of the brass colored valves because they match my bike components better. I don't use the plastic valve core remover that comes with these because I have valve caps with the valve core remover made into them.

Easy to install and, so far at least, properly functioning, these valves were installed on wide rims for 2.8 width tires, using Gorilla Tape to seal the rims for tubeless conversion. No leakage, and no clogging, as yet; but it's only been a week, so I can't yet comment on any long term experience with them.

Yes I will admit these things are a great deal. But with their low price they lack durability. I set them up with no problems but soon realized their weak points. If you do not fully tighten them to the rim they will leak a lot of air quickly. Overall if you are looking for a quick way to go tubeless these are a good options but if you are serious about cycling I would dish out an extra 10 dollars and go with a nicer pair

My tubeless tires and wheels worked great for years but the integrated rubber liner and valve stem developed a leak where they were fused together. I added new tape around the wheel, rotated the rubber liner, poked a new hole in the liner and installed these valve stems in place of the old, fused ones and it went in perfectly.It has been a couple of months now and the tires have held the same air pressure the whole time. Job done.

Not much to report. I screwed these valves in, put some sealant into the bottom of the tire, seated it on the rim a little bit, compressor on, et voila, I am riding tubeless (with tubeless-ready wheels, of course). No leaks from the valves or anywhere else after 2 weeks.

Quality was good and conveniently came with the core tool. My only problem was that the valve stems wouldn't seat completely when installed (WTB i19 wheels) as they were slightly too wide and the rubber too hard make an airtight seal, even when the nut was tightened with pliers.