These are quality inexpensive tubes. The valve stem is threaded all the way to the base and there is a nut that goes over the threads. This gives you the ability to secure the valve stem in place making installation incredibly easy.
The threaded stem is a treat. It makes it simple to fill, since the valve wont squeeze back into the wheel. Just wish continental would make them for my 29. Not into the presta thing. Try finding a presta set up in the middle of Costa Rica. First thing I do is drill out my tubeless to go old school. Peace
The Continental TourMTB 26 Tube has been amazing. Has held air for months now and no need to pump them up again. I have been storing my bike in my home so I'm sure that helps, but my old tubes required refill after a week. These tubes are much better. I've been riding on pavement and on gravel roads and no punctures or problems.
These tubes are made very well and I have not had any issues with them unlike other brands. It is really handy they come with a small nut to screw down around the value stem to help it in place. It is a big help when trying to inflate a tire.
Normally have great luck out of continental tires and tubes. But the first tube I had blew up while inflating at just over 40 psi. Had to run to the local bike store and pay twice the price for a lower quality tube. Kind of disappointing, but the other three held.
Quality looked good, but one of the tubes I bought ended up having a tiny pinhole in it near the valve stem. Rode to our favorite restaurant the day after I installed it and had to walk to the bike home with a flat rear tire. Tire was perfectly fine, no holes...so just a freak happenstance I think.
I have over 300 miles on these tubes with no flats. I am using good flat resistant e- bike tires. There is minimal weekly air loss. Far surpass original bike tubes as well as other replacements.
I got these tubes to match with some Continental tires bought at the same time. While I was installing the first tire, the tube blew out at about 50 psi, about a 4 inch long split. Could have been pinched, or a one in a million defect, I don't know. I never had a tube blow out like this before in 40 years. But since this was for my wife's bike I switched for some older Specialized tubes I had on the shelf that were a bit thicker rubber.
I run 1.5 semi-slicks on my mountain bike for road use. The standard 1.75-2.1 mountain tube does not install well and pinch flats. This tube solves the problem. The rubber thickness is a bit more and more reliable against flats. I have over 15 bikes and I am convinced the Conti tube is the best! Rumor has it that all tubes come from the same factories in China but for whatever reason the Conti tubes are the best quality, easy to install, but most importantly reliable. Get them!