Terminal Velocity

My lunch bike ride has some hills1As this route ends where it starts, I earn that downhill. at its northeast corner. At the top of Cedar Mills Blvd is a 40 mph sign. Challenge accepted!

Yesterday, as I crested the hill, I cranked to 20 mph,2That’s about the limit for Sage. She’s not geared for high speeds. tucked, and coasted. At the Barnes Road signal, I checked my max speed: 37.2 mph. Close, but this ain’t horseshoes! :-(

For now, I’ll have to be content knowing I can speed3Though barely… in 20 mph school zones.

Calculating my Bicycle Commute Time

This morning, as I was “enjoying” the moderating effects of a chilly headwind, I amused myself by trying to calculate how much longer my commute was taking.

My typical cycling speed is around 15-18 miles per hour, but because of the wind, I was going around 12 mph. My commute is about 3.5 miles. Dividing 15 by 3.5, multiplying by 60 to get minutes … argh! I can’t do that in my head.

So, I inverted my calculations and calculated how many minutes it takes to travel a mile at some common bicycling speeds.

Miles Per HourMinutes Per Mile
106
125
154
203
302

I noticed a couple of things as I pedaled along:

  1. Calculating my normal commute time got a lot easier: for example, 3.5 miles divided by 4 minutes per mile is 14 minutes.
  2. The headwind, although it slowed me down a few miles an hour, wasn’t going to make a big difference in my commute time: just 3.5 minutes.

Woo hoo!

So slow it down a little, take some pictures, and enjoy the ride. :-)

I wondered why these results are so counter-intuitive. Take a look at the vast differences in time depending on speed.

But look again. Most of the difference in time is for speeds less than 10 mph. For my short commute, there isn’t a huge difference in total time whether I go 10 mph or 60 mph. Better yet, there’s even less difference in time per mile for my typical biking speeds of 10 to 20 mph.

By the way, this is directly applicable to commuting by car, too.