Newton’s Laws of Motion

According to what I’ve read recently, Newton (the physicist not the cookie) came up with some laws that have been proven and supported. One of those laws, the Second Law of Motion, states that “The acceleration a of a body is parallel and directly proportional to the net force F and inversely proportional to the mass m, i.e., F = ma”.

Now I was never a good student, choosing instead to focus on the social and entertainment aspects of school instead of the traditional educational aspects, but from what I can determine, this means that a cyclist’s speed (acceleration) is directly proportional to the power (Force) they can produce and inversely proportional to their weight (mass) – And all of this is assuming no outside interference (wind, hills, draft, etc)

Well, with all the rain we’ve been having here in “sunny” California, I haven’t been out on the bike as much as I’d like. I have though been “fueling” for rides that never happen….which as you can imagine has increased my (m)Mass while not at all increasing my (f)Force.

Yesterday though, after church, the skies were only partly cloudy so I got my gear together, put air in my tires (they were low, not completely flat...it hasn't been that long), and headed out on the road bike for what I planned on being a fast, flat 20 mile loop that should get me home before the rains came back.

In planning most all of my rides, I try to include a decent amount of climbing. Its one of those things that, although it causes me much pain and suffering, I really enjoy. I like to climb. I like the way it forces me to focus on making circles and keeping my heart rate under control while preventing me from thinking about any of the other junk that is normally bouncing around in my head.

Yesterday’s route though was going to be almost completely flat so I figured I’d try to force myself into a similar state by ramping up my pace and hammering the whole route….unfortunately those stupid Laws of Motion that I mentioned above kind of got in the way.

At the end of last season, I found that I was able to maintain a pretty consistent 20-21mph rate on a flat road, riding alone and with little wind and including sections at 22-23mph. Usually this ended up generating an average of right around 20mph for a 20 mile loop. Yesterday though, after what seemed to me to be an all out effort, keeping my heart rate up and pushing hard, I got home to find that my 20 mile loop averaged 17.7mph per my Garmin.

Now, before you start calling me a fat slug, (which to be honest is the phrase I used after looking at my stats) I will say that the last section home, Mission Bl north to Industrial Bl. west was almost all either directly into a headwind or with a very stiff crosswind which were things that had a direct bearing on Mr. Newton’s laws (physicists call these mitigating factors)

The fundamental truth here though, ignoring my excuses, is that that the same force (f) applied to a larger mass(m+x) will produce a correspondingly smaller acceleration. Or more plainly stated, if I paid more attention to Mr. Newton and spent less time with Fig Newtons I’d be able to maintain a faster pace because my (m)ass would be smaller.