Review on High Performance 700x32-47 Continental Tour Bike Tubes - 4 Pack with 40mm Schrader Valve by Fernando Ramani

These are cheap inner tubes. But even though the packaging says 32-47c tires, that's WRONG. These are typical thin wall tubes, fairly light and will fit 32-38c tires but I would NOT risk more than 38c. I have a Trek Verve 1 with 45c tires. I went through all of these 3 packs in a month, smoothed out all 3 without doing anything else in either the tire fitting process or the bike method. The problem is that they are too thin walled to function in the larger space and airspace of a 40c or 45c tire, they can expand too much and then burst. For 40-47c tires you need a real, tough, heavy gauge tube that can handle the volume of air in your tire. I recommend Sunlite 40-45c tubes, these are very thick, strong tubes that will handle 65psi with ease.