Originally Posted by
PaulRivers
Plus if you read the road biking forums, the general sentiment is that bike weight doesn't affect your speed or effort once you're up to speed on the flat, it's just when accelerating or going uphill that it matters, one might think the same thing would apply in a car...
I'm an engineering type by trade, and I'm pretty sure from my memory of college physics that they are wrong on that, for both bikes and cars. It's not weight, it's mass, and friction, wind resistance, and other losses due to gravity mean increased energy requirements to stay at a steady speed on a flat with increased mass. It takes a given amount of energy to propel a particular mass at a particular speed, and increasing the mass mean you have to increase the energy input. Try pulling a 2,000 pound trailer with your bike and then tell me the added mass doesn’t mean you have to work harder just to maintain a speed on level ground.