Originally Posted by
bdcheung
Because gravity doesn't go away when the road gradient is zero?
So your saying the reason a bike moves "backwards" when a rider stands on flat ground is because gravity pulls it back?
Originally Posted by
nafun
It's not so mysterious. When some people stand, the first thing they do is pull themselves forward off the saddle with their arms. When you do this, you are pulling the bike back by the handlebars. If the first thing you do is push hard on the pedals and let your legs raise you off the saddle, then the bike doesn't jump back.
Is the correct answer.