Foss Inner Tube

I'm giving these bike tubes a generous 3 stars. I'll start with the good. The valve stems are just plain awesome! They look great and I wish latex and butyl tubes had these great looking valves. Now for the bad. For sure and certain, increased rolling resistance as compared to the standard butyl tube. They feel like your riding on solid tires. I had these tubes inside GP 4000s II tires and on my Trek 7.6FX. I rode my bike less than 10 miles on these tubes and the front tire is flat. Good thing it happened at home. I removed the tube for inspection. Seems that the round overlay that seals the valve stem to the tube debonded from the tube. I was very particular with installation and installed according to directions. To sum it all up, if there is a place for these tubes, it would be on a bike to look at. Not the one you ride. Or perhaps, on a mountain bike where low pressure is used and flats from thorns and such are a problem.