Gears are a way of trading power for speed, so that you can keep spinning at a comfortable rate regardless if you are heading up hill, staying on the flat or going downhill under power.
It depends on the bike if the engine of bike is heavy it has more gears. Usually 5 gears are max gears.
2 gears
depends on the model. from 2-7 gears
MotoGP bikes have 6 gears.
Depending on the bike yes most adult sized bikes have gears
if you don't keep your chain and gears on your bike greased it will rust and come off.
Changing Gears Flagstaff and the Mountain Bike - 2011 was released on: USA: September 2011
Depending on the mountain bike that you have will depict the amount of gears. Most bikes for adults typically have about 21 gears. If this does no answer your question then what are levels?
To change gears on the bike, all you have to do (while riding it) is press the B button. You don't have to hold it in, either. ~Lucario
a track bike, or a bike with internal hub gears.
Unfortunately, you can't change gears on bikes in HeartGold.
I think you mean bike gears, because a faster speed means a better time (the shorter it will take you to get to wherever you are going).That's just common sense.With bike gears though:Higher gears are tougher to petal but allow you to put more push into each stroke.Lower gears are easier to petal but you will petal a lot more often per rotation of the bike wheels.Example: If on high gears it takes you 5 pushes to get to your destination, it will take you 15 pushes with low gears.