Here is an interesting story...
I deleted Vans tires and tubes from my finish kit and bought Michelen Air Stops from Desser six years ago based upon recommendations from fellow pilots sayimg that the Airstops are "the best"!
Since then, i finished my plane and flew it for about 170 hours in six months! They lost very little air during the three year period that it took me to complete the build! Then it came time to head to Oshkosh...
When I was about to leave, I discovered that I had a flat tire!
Hmmmm, the culprit was a pinhole in the Michelen Airstop. I circled it with a silver sharpie and brought it to Oshkosh where I promptly stuck it under the nose of the Michelen Rep who was there at the Desser booth.
He said that they recognized a manufacturing error in that series of tubes and comped me TWO NEW ONES! They just arrived yesterday and I plan on installing them inside the two new tires that I bought from Desser at the show!
Bottom line, faith in Michelen is restored and I will try my new Airstops and report back!
Give Michelen Airstops a try!

CJ