Originally Posted by
Burton
I guess it depends how you look at things. 'Puncture resistant' tubes made of thicker rubber aren't impervious to perferation by metal wire bits from steel belted tires. One puncture and you're still flat. Any sealant filled tube, on the other hand, can protect against multiple perferations and you probably wouldn't even notice.
Actually the sealant thing is not entirely correct. The more penetrations there are the less sealant is available to seal a leak until eventually, usually after about 3 or 4, you're flat. And some sealants like Slime doesn't work that great (at least their old version, I haven't tried the new version nor do I want to), and all sealants add weight.
Myosmith is correct when it comes to road tires, the first line of defense against flats is the tire, the only truly effective second line of defense against flats is a tire liner like the Panaracer FlatAway which is the best and lightest on the market. Tubes should never be used as a line of defense, in fact if you have a great tire like the Specialized Armadillo Elite, or Armadillo All Condition, or Continental Gator Hardshell (which might no longer be made) or perhaps the new Conti Grand Prix GT?, the Bontrager Hardcase, or numerious Schwalbe models especially the Marathon series, all you really need is an ultralight tube.
Liner wise the Mr Tuffy's or the Slime liner can cause flats! After about 1500 miles of riding the liner chaffs a hole in the tube, the only answer to that is to sand down the overlapping end that will contact the tube till it's paper thing. But Mr Tuffy's and the Slime liner are not that great, they work ok, but not as good as the Panaracer FlatAway, and the FlatAway is about 70 grams lighter.
But unless you have worries of getting a flat to work, or live in a throny area, or don't know how to repair flats and want to eliminate them as much as possible, most folks living in normal areas don't need heavy flat resistant tires.