Originally Posted by
cplager
Nobody rides at a constant speed. There are variations. So, yes, your acceleration is never 0.
That being said, your acceleration when climbing a hill (particularly if you are spinning instead of mashing) is going to be very small, so that the effect of the wheel weight when climbing will be much closer to a factor of 1 (meaning that the weight of the wheel is as important as weight anywhere else on the bike/rider).
As far as whether or not it is inconsequential, even with a factor of two, 200g of extra wheel weight is as bad as 400g of extra weight on your bike (which is just under 1 lbs). In my case, I ought to lose about 15 lbs myself, so I'm not going to do anything extreme to lose 1lbs of my bike.
Added:
A couple important points here:
1) When accelerating a bicycle, you need to not only accelerate the wheels (both linear and rotational sense), but also accelerate the bicycle and the rider. If you compare the mass of the wheels to that of the bike and the rider, you'll see that the wheels are are very small part of a bigger picture. So, yes, it takes more force to accelerate a heavy tire than a light tire, but not (relatively speaking) a lot more force to accelerate a rider, bike, and a "heavy" tire compared to the same rider, the same bike, and a "light" tire.
2) When you are moving at a constant speed, you only need to provide enough power to overcome the frictional forces against you. It will take less energy to keep a heavy but low rolling resistance tire moving than a light but high rolling resistance tire.
I'm at a loss to understand how you can hinge your whole argument on this 'constant speed' concept and how it means the rider doesn't have to input energy to maintain that speed, then concede 'constant speed' doesn't really exist and that riding is, in fact, a series of constant accelerations while pedaling, yet maintain the position that tire weight doesn't matter. Can you explain what I'm missing here?
You also seem to be certain that riders cannot notice, or feel, the weight difference between light and heavy tires, but I don't understand that position, either. If you accept, as you said above, that heavier tires do require more energy to acclerate than lighter ones, why would a rider not be able to sense that difference? We can feel the difference in power it takes to smash a grape under foot, and probably even a tender raspberry, so the idea that we can't feel how much resistance we're facing through the pedals doesn't smack true. I don't know how much force it takes to smash a grape compared to the force it would take to accelerate a 950gm tire versus a 210gm tire (same wheel/gear), so maybe you could address that.
Lastly, if you maintain that tire weight doesn't matter, how do you account for the widespread believe that it does, and the pursuit of lightest possible weights in all matters related to energy efficiency in vehicle development, whether bicycles, human powered vehicles, cars, and motorcycles?