Ok I am sick and tired of flats and this is only my second flat. I was running that 739 dunlop on the front and the stock tube with no flats. The only thing was was that I hated the 739 for cornering. So I switched to the IRC VE35 front tire. Since then I have had two pinch flats. The first with the stock tube the second with the Fly utra heavey duty tube. I try to run around 20psi to keep from getting pinch flats. So is it my tire that is to week and causing me the pinch flats or what. Now I will admit that everyone told me that I needed to check my tire presure before every ride with the Ulta Heavy Duty tubes because they are a "Natural Rubber" and the tend to leak. Well I would say they are right they leak and tend to go down in presure about every four hours. Now I know that I did not have a puncure from a nail or anything else because I had slime in the UHD tube as well. So at this point I am not sure if the Tire I am running is the weak link or the Tube. I will say that if I am going to get this many Pinch Flats that I am going to just buy the cheepie tubes and a $%it load of patches. Did I mention that I love riding rocks! What do you think?