I've had dreadful luck with bonty tubes . . . when I first purchased my bike, I had roughly six flats within the first month. It wasn't until I changed tube brands, that I stopped experiencing flats. I've been using Conti's for the past 8 months and have only had one flat. My LBS told me that bontrager, for whatever reason, when a "line" of tubes is produced, and there's a defect in one, chances are, that entire shipment will have that same defect. Therefore, on some occasions, they have had to return their bonty tubes (w/ same production line #) when say 5 or 6 riders come in complaining of the same problem. Since my LBS doesn't carry Conti's, I just order them online - they're much cheaper too