I've tried the Walmart crap and they're ... well .. CRAP! Leaky valve stems, little holes, even dryrot.
After much anger, I went to my local bike dealer and asked for Heavy Duty Mountainbike tubes. He brought out a set and I was expecting to pay double the price of what Walmart charges. But to my surprise, they were actually a few pennies less! :shock: I'm hook on them! They're really thick almost like a car tube. I weigh about 280 and they don't even wimper when they feel my weight. I've bought several sets and they all have different names but I believe that they all are Kenda made. Around here they run between $7.00 and $9.00 dollars each. The Walmart crap is usually $7.00 to $7.50 and you aint never gonna find a heavy duty tube at their store!
This is the best investment you can make for your bike if you plan on riding it!
Chainsaw