Review on 🚲 Continental MTB Bicycle Tubes - 26, 27.5, 28, 29 (1.75-2.25) with Presta Valve 42mm - Value Bundle of 5 Bike Tubes by Shaun Stapp

These hoses would be good if it weren't for the fact that the valve cores unscrew too easily. If you are using a screw-on type portable pump (meaning the pump hose is screwed onto the valve), when you inflate the tire (after replacing the ruptured hose) and unscrew the pump hose from the valve stem, the valve core comes out and all the air comes out of the tube. This has happened with EVERY one of these tubes. I have never been with my regular Kenda (Q Tubes) from my LBS. I was stuck pumping and deflating the tire for 45 minutes until I managed to get the right angle/pressure to disconnect the pump hose without losing all the air. No matter how hard you try to tighten the valve core, it comes loose too easily.