i did my usual and,googled about this.read a lot of stuff about it and, tried a few things.
the tire that the tube blew up on, i switched to the front wheel.
then i switched my front tire onto my back rim. but it still didnt feel right.
so i went and got a different tire. a gumwall made by -national tire company- and voila,problem solved.
ALSO,MY AIRPUMP IS CRAP. I am learning not to be to cheap. just on a lark when i switched this stuff around,i took the tires to my -LBS- and used their blackburn pump.
my pump had said 70 psi, but it didnt even register on the blackburn pump.
so i pumped them up to 70 and,i couldnt believe the difference. i bought a -real-pump at my LBS, And i think i will shoot them up to 80 psi and, leave good enough alone.
BUT THE POINT I WANTED TO MAKE WAS-some rim and tire combos dont play well together as i found out.some do.
so maybe if your having the same failures,try switching things around.