Dave Cutter

+1
If your going for distance... slow down.. and take a break. Make a day of loops near home... if it makes you feel more secure. Stop for a coffee, or get a cold vitamin water from a gas station, even stop at a park area that has shade.

DTSCDS

Let me see if I can help on the gearing issue.

First, terminology. The 'gears' up front where the pedals are--those are generally referred to as "rings". (As in "chainrings") The whole thing as a unit--gears, pedal 'arms' and the internal bits--is called the "crank" or "crankset".

The gears at the back, on the back wheel, are referred to as "cogs". The rear group is also collectively called a "cassette" (for older bikes it can be a "freewheel" but that is really beside the point--they all do the same thing.)

Now to what is really important. . .You said you have 3 'rings' and 7 'cogs'. So technically you have 21 gears. Instead of thinking of it as 1 to 21, IMHO it is better to think of it as combinations of the front and rear gears. Here is the basic idea--the smaller the ring (front), the easier it is to pedal but the slower your speed will be, the bigger the ring the faster you will go but pedaling is harder. With the cogs (rear) it is opposite--the larger cogs make it easier to pedal but slower. . .So, you easiest to pedal combination, and therefore easier to climb hills, is your smallest ring and largest cog. Your fastest combination will be your largest ring and smallest cog.

On relatively flatish ground, you are going to spend the majority of your time in the middle ring and just switch out the back as needed. Why do you switch you ask? To maintain a steady pedal rhythm (known as "cadence"). For most of us, a decent cadence is about 80-90 rpm. The faster you "spin" the pedals, the less energy your legs have to expend. Think of it this way, however many squats you can do, that number is going to drop as you add more weight. The harder you legs have to work the quicker they are going to give out.

So, for mostly level ground, put yourself in the middle ring and find the right cog in the back to pedal around 80'ish rpm. As you start going uphill, you will change to a larger cog to maintain the same cadence even though you will be slowing down. If you get to the next to largest cog and are still going uphill, time to switch to the smallest ring. Start going downhill, time to switch to smaller cogs. If you get to the next to smallest cog and are spinning faster and faster, switch to the large ring.

The only thing to avoid is "cross-chaining"--using the small ring and small cog or big ring and big cog combinations. Those are hard on your chain and gears.

You are highly unlikely to break your chain since this is a relatively new bike. Don't be afraid to change gears, that's why you have them.

DTSCDS

If I had seen there was a second page of posts I would have known that TXsailor already covered the gearing thing.

Carry on.