It has been a long time since i have cycled and i just bought me and my girlfriend mountain bikes with 21 gears. To make my question simple i will talk in simple terms so forgive me if i call a part something other than waht it is. I understand how gears work but my question is how do you know what gear you are in? I have a controler on the left handle grip that has 3 positions and on the right a controler that has 7 positions. I know that it should be a straight forward understanding but my owners manual is not making it sttraight forward. for instance, if the left controler is in gear 1 then the right controler shoul be shifting throught gears 1 through 7. As you switch to gear 2 on the left controler then you should be able to shift through gears 8 through 14.
This brings me to another question. What gear would you start in on a flat level surface?
Most of the time you will want to be in gear 2 on the left, and do practically all your shifting with the right shifter. On the level it will probably be comfortable to start off in gear 3 on the right. When your feet feel like they are spinning too fast you shift up to 4 then 5. If you feel you are having to push hard on the pedals shift down to a lower gear. Gear 1 on the left is to get you up steep hills, and shifting from 2 to 1 on the left is the equivalent of shifting down 3 gears on the right, so the time to make the shift down on the left is when there is a sudden change of gradient. Sometimes when you shift down on the left you might want to shift up on the right to keep your feet spinning at a reasonable pace. You will only want to use 3 on the left when you have a strong tail wind pushing you along, or on a long downhill.