My wife and I have been using Mr Tuffy's since we got our touring bikes in 2000. Never had a flat caused by the liner. I think we have had a grand total of 5 flat tires in that time period-4 for me, 1 for her,and all caused by wire from shredded tires going thru the sidewall above the liner. I did replae the tubes after about 4 years and a few tires because there was a line form the end of the tire liner, but no cuts thru it. I really can't see how you could mess up installing them, unles you didn't bother getting them to lay flat in the tire. The only installation tip is to stretch them out flat until they lose the curl, then put them into the tire. I would think if you don't keep the tires up to pressure that they may tend to move and potentially damage the tube, but I've never heard of anyone getting flats every 50 miles from them. Between the wife and I, ours must have about 30,000 miles, and never caused a flat.