Originally Posted by
saddlesores
that was my understanding of the first couple paragraphs in that article.
"According to Wheel Energy, the key to reducing rolling resistance is minimizing the energy lost to casing deformation, not minimizing how much tread is in contact with the ground. All other factors being equal, wider casings exhibit less 'bulge' as a percentage of their cross-section and also have a shorter section of deflected sidewall."
.........which should indicate solid rubber tires will even faster.
That's close, but if stated more correctly, WE's conclusion would be suspect. Correctly stated, rr depends on the cross sectional area being deformed, the amount of deformation, and the material being deformed. "All other factors" are never equal. "Wider casings exhibit less bulge" only when inflated to the same pressure as narrower casings. Etc.
IME all tubes which are not defective in design or manufacture and weigh about the same, are about the same. Of course some runs of some tubes have defective valve attachments and defective valves. I've run across these problems with many brands of tubes, regardless of country of manufacture. I've even purchased name-brand tubes which were too long and didn't fit in the tire unless folded. That wasn't good.
Thicker tubes do lose air more slowly. This is only an advantage if one has an inadequate pump. On our recent tandem tour, we ran thick 28-32 tubes for the first time. Since we pump to 120 psi, it was rather nice not having to pump every morning, as even pumping to high pressure with a Road Morph is not the most pleasant way to start the day. We carried thin 19-26 tubes as spares.
Tubes deform right along with the tire. I'm sure thicker tubes have a higher rolling resistance than thinner tubes.
I've not found that thicker tubes flat less often than thinner tubes. Maybe it takes a little longer for the glass or wire to work its way through a thicker tube, but through it goes. I've not used slime tubes.