Originally Posted by cyccommute

It depends on what kind of touring I'm doing. For rides that are paved roads rides, I don't carry a filter. If I'm going backcountry touring, I carry one.

I have to disagree on the Sawyer, however. I did a 3 day mountain bike trip this summer and the Sawyer failed miserably. I had only used it once before and it seemed to work well, however, I had trouble getting it to flow at more than a few drops per minute on this trip. The previous usage had be, literally, once and I had filtered clear water so the filter shouldn't have been clogged. The first night I used it, I had to squeeze the bag for about 2 hours to filter a couple of liters of water. My hands cramped up so badly that I had to pry my fingers off the bag. On the second and third night, I let gravity (and a rock) do the squeezing but it still took hours to get enough water to drink or cook with.

The squeeze bags are a second problem. You can't fill the bag by simply dunking it in a stream. The bag collapses. I had to carry a water bottle to fill the bag so that I could try to squeeze water out of it...or so that a rock could squeeze the water out of it. Also, if you happen to damage the bag and aren't carrying a spare, the whole system is useless. If you want my filter, you might find it on a picnic bench at Mirror Lake on the other side of Tin Cup Pass. I left it there.

I'll carry a heavier but more reliable MSR or Sweetwater filter in the future.