Tuesday, May 29, 2007

Speed & Distance

One of the features we have on our bikes are "bike computers". They tell current speed, and maintain basic statistics. The overall odometer tells total distance traveled. Resettable trip odometers, average speed, maximum speed, and biking-time-elapsed are all statistics maintained since the last reset. The computers work simply. There is a magnet attached to one of the spokes on the front wheel, and a sensor attached to the bike frame next to the wheel. Each time the magnet passes the sensor, another rotation of the tire is counted. When calibrated for the size of the tire, the device calculates the distance traveled. To those not familiar with biking, this might seem like a nice little discretionary bell or whistle. In reality, the computer serves as a vital tool as we travel. We could not easily do without them.

Obviously, the computer is the source of the information we have been providing as to how far we've traveled. More importantly, though, we consult them continuously during our rides as we follow our route map. Key landmarks, turns, etc. are all identified on our maps based on distances. The map tells us things like: "From the town of Coatopa, go 7.5 miles, then turn right on Bluffport Rd /Country Route 21." The computer helps us figure out where we are, and when we should be anticipating the next turn or landmark. And since some turns are on roads that are unsigned, if you can't track the distance traveled, you could become seriously lost!

The speed feature of the computer serves as an important calibration point for us as we travel. We have generally been averaging 9-10 miles per hour during the course of a day. We are not particularly strong or fast riders -- others may laugh at those speeds. But the point is that we know that that is us. And so when we have a long stretch moving at 12-13 mph, that signals some pretty good progress. Climbing hills can bring us down to 6, 5, 4 or even 3 mph, and we just learn that that is part of what makes up the average. In general though, knowing approximately how you are doing on speed, and knowing how much further to your destination, allows you to calculate that all-important "how much longer 'til we get there?" number!

(By the way, at 3 mph, you might wonder how you can even stay upright on a bike. To tell you the truth, I'm not sure either. I do know that at that speed, you are going slow enough that bugs land on you while you bike. I guess they assume you are walking!)

Maximum speed is mainly a fun statistic to know. Building up speed going downhill is probably a topic all on its own. The speed may seem very slow and boring when in a car, but when you exceed 20 mph on a bicycle, you are in for a sort of sensory adrenaline rush! Now, we are not into trying to set downhill speed records, especially with our heavily-loaded bikes, and usually we just coast our way down (vs. pedaling like madmen to go as fast as possible). If there is any doubt about our stability, we apply brakes on the way down. Still, at various points along the way, we have each hit maximum speeds into the 30's. It makes up a bit for the fact that we may have climbed that hill at 3.5 mph in the first place!

Finally, and this is more of a facet for me (Mike) than for Joan, but the computer also serves as a source of mental gymnastics to occupy time or take my mind off the pain of a long ride. I find myself doing the arithmetic in my head to figure out distances and times between different landmarks. And on those really terrible days, when I am struggling up what seems like the 50th consecutive massive hill, my legs aching, the mid-day sun baking, the crest of the hill seemingly never getting any closer..... I watch the most detailed distance counter on the computer tick off, ever so slowly, the 1/100ths of a mile. I have even calibrated that to the number of times I crank the pedals in the lowest gear. (Tamara & Dawson, don't laugh!) It takes about 12 turns of the pedal to get me another .01 mile. And so I count my pedal turns: 1, 2, 3, ......, 11, 12 -- another .01 mile (52.8 feet, or 16.25 meters) behind me! This mental approach may not be for everyone, but somehow it helps me get up the hills.


Tamara Smith said...

Hey! We're famous! Thanks for mentioning us by name in your blog! I did smile - sounded very just like Mike! I don't know how you do it with counting - give me a good old fashioned day dream anyday!

Mike said...

If you are famous, then it is from something other than this blog, I am sure! I meant in a previous entry to thank you publicly for your quick internet research on our behalf regarding the handlebar issues with our hands. That really helped us out a lot, so I will thank you now!