>>1969280As previous anon said, geometry matters a lot. On a bike where you're leaned further forwards you're in a better position to shift your weight around for handling, and are always able to put more force into the cranks when compared to a bike that you sit more upright on. But the trade off is that unless you're strong and fit, it's more comfortable to ride in a more upright position, largely because a higher percentage of your body weight is being carried by the saddle.
