It is important to make sure you are as familiar with your
bike as you can be before you challenge it and yourself. When advising you on
how to choose the right bike size for you, the hardtail of the bike was
mentioned. But as many of you might have noticed, some mountain bikes don’t
have a hardtail running all the way down, and instead have a complex suspension
setup. Those are called full suspension bikes because they have suspension both
at the front and at the rear, instead of just the front. The reason why you’re
not likely to begin with a full suspension bike is the added maintenance, and
more importantly the extra cost. So we’ll speak mostly in the context of the
What your mountain bike is almost certain to have is gears. Some beginners dread the shifter as much as beginner drivers dread the manual transmission. Shifting gears makes unpleasant noises, makes pedals dip unexpectedly sometimes, and if gears are shifted too enthusiastically, especially on older bikes with rotary gear selectors, the chain falls off. These problems are mainly due to inexperience or not knowing exactly how to take full advantage of the gears. The gears are your friends, allowing you to change the amount of force you need to apply to retain momentum on every kind of terrain you encounter. If you are looking for a bike, look for a “one by”. A “one by” is a bike where the pedal axle has only sprocket, with multiple sprockets at the back wheel. So depending on how many sprockets your bike has at the back wheels, it can be a 1×6 or a 1×8 or a 1×12, etc. Having only one sprocket at the pedal axle means that you will only have one shifter on the handles. Change up a gear if you are on even terrain and looking to go faster, and down a gear if you’re at an incline and need the extra leverage. Another common configuration is a “three by”, and they are surprisingly widespread even among the cheaper bikes. That’s where all of these crackle and chain slip horror stories come from. There are three sprockets on the pedal axle that you need to shift between separately. With those, you have two sets of gear selectors one on each side, and shifting them becomes a little more complex. Stick with a “one by” for now. It won’t give you the flexibility of a greater range of gearing, but you’re unlikely to need it as a beginner. And the simplicity of having just one gear selector will mean that you’ll get used to your bike faster.
Once you know how your bike behaves and how to use its configuration most effectively, you can start choosing a trail. There are plenty of websites that will help you find mountain biking trails of varying difficulty in your location. Take full advantage of those, and ask around for what would be the most fun trail to begin with.