When I ordered the Continental Top Contact winter snow tires for my commute bike, I went with a wider tire for dealing with snow, and for extra security, ordered these new tubes to fit the new tires. The last thing you want in winter commuter conditions is to have to fix a flat in freezing temperatures. These tubes got me through winter and snowpocalypse with no worries. Also, the shipment of tires and tubes arrived in just 2 days, all the way from Portland to my front door in Wenatchee. Usually I go with the LBS, but they told me the tires were not available and out of stock. Biketires direct got them to me right away before the snow hit.
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.
With Covid19 it seems that I'm resurrecting older bikes for family to ride. It's usually best to start them off on mountain bikes because they are more stable to ride, especially for newer or long away riders. Getting rid of the old 26 heavy mountain bike tires is the first step. I stick with Continental tubes because I'm happy with Continental tires.
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.
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.