In racing bikes, ideally as much as possible is carbon because it's light. However, generally moving parts are made of other materials as carbon is not great for that kind of thing.
Yes, the Amish people can and do ride bikes all the time.
Yes, many people ride bikes.
Practice....
No
Because it's awesome. I ride mountain bikes competitively; however, dirt bikes add an extra dimension of fun.entertainment. people ride because its fun to do. it can also be for compitition, or even transportation.
yes
Because it's fun!
Ride Bikes Ride Bikes
They play baseball or ride bikes.
only if he or she wants too
Wherever they wanted, could, and were allowed to.
To help prevent pollution people could walk, ride bikes and use public transportation.