Help with my Mountain Bike Gears!!!!!?

I just got a new Diamondback Sorento mountain bike but never had a bike with gears...used to get cycle bikes

but

how the hell are you supposed to use the gears..

i have a slight idea..but i have no clue..

all i kno is..its a 21 speed

and WHEN am i supposed to change gears..

everytime i do..theres this displeasing crunching sound

like i'm breaking it or something....

is it ok to change while biking...

and will the sound go away when i start to learn how to use the gears properly?Help with my Mountain Bike Gears!!!!!?
First, there is a thing or 2 to understand when shifting your new bike.



1) You must be pedalling anytime you shift... this means no playing with the shifter when standing still, and



2) Looking at the shifters, when both are at ';1'; you are in ';easy'; gear, and when they are at ';3'; and ';7'; you are in ';hard'; gear.



To shift:



Get on the bike and start riding. As you pedal, shift one side or the other... but not both at the same time. Lower numbers mean easier gears (like for going up hills), higher numbers mean harder gears (like for on flat areas or for picking up speed).



Move the shifter only until it 'clicks'. It should go right into gear. If it doesn't it probably needs a quick cable adjustment... this is VERY common on new bikes, there is nothing wrong with it.



Try and shift your bike to lower gears BEFORE going up inclines. When placing a lot of pressure on the pedals the derailleurs don't like it (but you won't hurt anything).



There is only one gear combination that you shouldn't use on your bike... that is ';3'; on the left side (front) and ';1'; on the right side. This places stress on the chain and will always make noise.



Make sure to take your bike back for the free checkup. Things settle in and stretch during the first few rides and adjustments will be required to keep your bike riding right.



Have fun!Help with my Mountain Bike Gears!!!!!?
The big gear in the front coupled with the smallest gear in the back is your high speed gear, for going down hills or with the wind at your back



Reverse this ... little gear in front and big on in the back is for going up hills.



some combinations you are not supposed to use ... bi in front and big in back.. hard on chain and lots of things.



same with little in front and back- don't use.



start off with the chain in the middle gears front and back and just move the rear gears.



then back to the middle middle and just move the front chain rings.



stay on the flat for a while and see how minor changes affect your speed and resistance.



only move one gear at a time.



good luck
it's best to shift only while you are pedaling.. don't shift then pedal it feels bad. shift down when you go up a slope or come to a red light ( so you can accelerate easy when light turns green)

as you gain speed and you pedal faster, shift up



DO NOT SHIFT WHEN YOU ARE NOT PEDALING