the gears and where the axis of the wheels
Everywhere where parts are meant to move easily, like in bearings.
M
Um.spjn.Siemens
I'm not sure.
In the bearings, where you want as little friction as possible.
The brakes! And the tires (no friction = no traction).
In any part that you want to keep moving, like a spinning wheel, friction is just a nuisance.
hedtrdutfydfufuf
The bearings
Friction can be a nuisance when it causes wear and tear -- on parts in machinery, on items of clothing, furniture, etc. Friction can also be a nuisance when it causes static electricity. The static electricity, depending on the circumstances, can cause anything from a mild shock and clothing cling to an explosion at a gas pump or near gas fumes in a building. It can also cause damage while work is being done on the insides of a computer.
Ice skatingIn any electric motor. The friction causes the motor to heat up and waste energy.
Because friction stops momentum of force from moving the bike
The brakes and the tire treads.
Friction and leverage.
Friction and pressure.