It started as a heated discussion between me and a colleague about whether tubes pre-filled with slime are a good idea. I didn't think so because the tubes are heavier. Since we couldn't convince each other, I did some research online and found some
intersting bicycle science. Following are a couple of excerpts:
What keeps a bike upright?
This is a classic trick question, as many people with some high school or college physics assume that it is the gyroscopic effect of the wheels that keeps a bike upright. But this is not the reason, and experiments with bikes that have counter-rotating wheels have demonstrated so. The reason a bike stays upright is largely two-fold: rider balance and "steering trail." Rider balance is simple enough to understand, but steering trail requires some explanation. Steering trail refers to the effect produced by the design and geometry of the front part of a bike whereby it tends to slightly correct itself when the front wheel is turned askew from the direction the bike is going. You can see this effect by holding a bike from its seat, pointing the bike north but pointing the front wheel slightly to the left or right and then pushing the bike forward. Notice how the front wheel adjusts itself towards the direction of bike motion. As for the gyroscopic effect of the wheels, only at very high speeds with heavy wheels do they begin to have any significant effect. A simple way to see how little effect gyroscopics have on bike balance is to prop your bike on a curb with the rear wheel off the ground while spinning as fast as you can get it. Then push the bike over. Notice that it falls over just as easily as when the wheel is still.
How much does wheel rotating weight matter?
It is a common misconception that the rotation of wheels makes their weight much more significant than non-rotating weight. The truth is that this effect only applies to wheel acceleration and even so is such a small effect as to be nearly nonexistent. Any steady-paced ride, whether it be on flat ground or up hill, does not involve acceleration and so in this case there is zero rotating weight effect. In the case of wheel acceleration, it has been shown that the weight of wheels is so small compared to the weight of the rest of the bike and the rider that the rotational effect is almost insignificant. Note that all the best professional and Olympic track sprinters today race with heaver carbon tri-, quad-, and penta-spoke wheels instead of racing with lighter weight spoked wheels.
