It's not hot air |

I generally ride my bike every morning. Sometimes I ride it in the afternoons, too.

But, since the end of Pesach, it has rained so much and so long that my bike riding has been pretty much missing from my daily activity logs. As a matter of fact, one night when I was returning from a business trip to Baltimore, the Rock Creek Parkway was underwater (that was announced on the radio), as was the road I was on (instead). Kenilworth Avenue/DC 295 had significant flooding that forced me to back up on an interstate (the first time I ever did so) and execute a very long detour. So much for getting home by midnight.

And, yesterday (when this was written) was the first time in a long time that we had no rain. So, I took the tarp off my bike and began cruising. As I was pedaling, I was thinking how much out of practice I must have been. Because instead of my normal 18 mph cruising speed, my speedometer was topped off at 15.

I figured I had a few days of such effort before things returned to normal. Except I passed a friend’s shop (he runs a bicycle coop) who screamed out that I needed to put air in my tires.

Bingo! That was probably the reason. And, when I got home, I cranked up my pump and brought the tire pressure up to 75 psi.

The next day, I was moving along just fine. And, I realized that too many of us fall prey to the same situation. We don’t check the air (ok, nitrogen) in our tires every time we fill up our cars with gas anymore. Mostly because the service stations don’t provide air (or nitrogen) and don’t have tire pressure gauges.

But, it’s absolutely true that like having my bike speed drop about 10%, our gas mileage drops about 10% when our tires are underinflated. And, our ride is much smoother when the tires are properly inflated. Riding my bike- I can tell how much more energy I need to achieve cruising speed. Driving my car- it’s just an imperceptible increase in foot pressure on the accelerator.

And, we use nitrogen in our tires because, as opposed to air (which is primarily nitrogen and oxygen), the gas permeationout of the tires is much lower. It’s the oxygen that can pass through the rubber easily, not the nitrogen. Nitrogen doesn’t accumulate as much moisture as oxygen, either- so there’s less water vapor that can affect tire pressure. And, with tubeless tires, it’s great to know that the lack of oxygen means rust (oxidation) won’t form on our tire rims.

So, even with the lower price for fuel, do yourself a favor. Keep your tires properly inflated.