Hello all, I was on my way to meet my wife for lunch today and I have unbelievably destroyed 3 tire tubes today, 2 kenda and 1 forte 700x28-32c tubes. The tires I have are continental gatorskins in 700x28. To describe myself im a bit less than 250 pounds and 6'4" tall. As I was preparing my bike this morning I noticed that my rear tire was flat so The first thing I did was uninstall the rear tire and tube. To my discovery, the area where the presta valve is connected to the whole innertube, incurred a hole right around the edges of the valve. Okay, so I put in another kenda innertube and pumped up the tire. As i was nearing 100psi, i hear air start to come out of the presta valve. So, again, I unmount the tire and notice that the same problem arises - the area around the presta valve where it connects to the innertube has started to separate AGAIN. Okay, so I was going to call it a day until I found one last innertube, a forte 700x28-32 in my parts box. I install that tube and everything checks out aye-okay. I get on my road bike and embark on a 11 mile journey to my wife's work to meet her for lunch. As I approach 7.54 miles, I thought a turbo'd WRX was driving by me and showing off its turbo but no, that was the sound of my innertube going out AGAIN. So I take a look at the tube and again, its the same problem that im not even going to type since ive already fat-fingered several words using my iphone 4s to type this all out any particular reason someone can give for this? Is it the lock ring on the presta? I kept it somewhat snug but more on the loose end during the 3rd tube today. Any help or input is appreciated, thanks!