I just tried the Challenger latex tubes. They are in the low 60s gram range. I also put 105 psi in the front tire and 110 in the back. I didn't have any trouble for 350 to 400 miles. Then, as an experiment, I decided to go back to the 120 psi I had been using in both tires. The wheels did seem faster, but in less than a mile I heard a big bang; the tube was blown outside the tire (only the valve stem was inside the tire). So, I am not sure what I will try next. Maybe a lite butyl tube. Maybe stick with the latex but just stay around 100 to 110 psi. The latex tubes do leak faster than butyl tubes, but that did not bother me. I ride almost every day and I could get two rides out of an air job. Was this just a freak accident. If you use latex tubes, do you inflate to 120 psi without having any regular problems?