You folks have to stop this! You made me think again! This is terrible.

Let us suppose that what we want to avoid are pinch flats. Let us further simplify by assuming that a pinch flat occurs when the rim contacts the road surface (even though it doesn't quite). So I made a quickie AutoCAD drawing of a 622 wheel with 23c and 32c tires on it. One obvious thing is that wider tires aren't just wider. They are also deeper in section by about the ratio of their widths. So let us assume that our tires are approximately square in section, i.e. 23mm X 23mm and 32mm X 32mm.

Drawing this out, we see that when the rim contacts the road on a 23c tire, the contact patch is 9.65" long, whereas on a 32c tire it will be 11.46" long. If we ignore the flattening of the tire and just use the specified width, we get a contact patch of 8.74 sq. in. for the 23c and 14.44 sq. in. for the 32c.

Our tandem carries a 300 lb. team. We have racer friends who run 23c Vredesteins at 140 lbs., and they are quite a bit heavier that are we. But they are so fast that I decided to run the same tires, which in fact work perfectly for us. So we multiply the 23c 8.74" patch X 140 lbs, getting 1223 lbs. Multiplying the 32c 14.44 patch X 95 lbs., we get 1372 lbs.

Thus for a 400 lb. team to blow both tires, they are taking a 3g hit, which is quite believable, and the 32s offer some margin, but not that great. We could pump our narrow tires higher, to get more pinch flat resistance, but the rims won't take it. The rim pressure limit for wide tires is obviously much lower than the rim limit for narrow tires.

Wide tire advocates, like Jan at BQ, ignore the higher pressures possible with smaller tires. Tire resistance comes from two sources: wind resistance and deflection. Wind resistance is obviously lower with narrow tires. Deflection resistance is due to the deformation of the tire carcass. The energy absorbed becomes heat energy. That's why you can blow a tire on your car by running it at too low a pressure. The heat comes from the deflection of the material and has three modifiers: 1)Amount of deflection 2) Width of material being deflected 3) Thickness of material being deflected. Which last two terms may be multiplied together to get area of material being deflected. Hence the thinner the tire carcass, the lower the rolling resistance.

Assuming a 225 lb. weight on one wheel, 140 lb. pressure produces a 1.6 sq. in. contact patch. At 95 lbs. pressure, we get a 2.37 sq. in. contact patch. Dividing 1.6 by 23mm, we get a 1.77" long contact patch. Dividing 2.37 by 32mm, we get a 1.88" long contact patch. So we see that the 23c tire deflects less at the same loading, and additionally has less material being deflected, hence its rolling resistance is less. However, the 32c tire has a greater resistance to pinch flats, as it is a taller tire.

If the above were not the case, racers would not be using the tires they use.