Cycling is technical as well as physical, and you need to know how to brake, change speed and use all of your bike's functions.
> On the road, you're better off with just a few gears (a small gear-change control with a large front chain wheel). Change gears if the relief changes to go up or downhill, and keep pedaling while you change them. When going downhill, use your front brakes if it's a gentle slope and your front and back brakes if it's steep.
> On rougher surfaces, a larger range of gears is better (with a large gear-change control and a small front chain wheel). Because your surface may be irregular and unstable, you need to brake earlier but less harshly than you would on the road, to avoid blocking your wheels. Carry on pedaling when you change gear, but don't pedal as hard, especially if you're going over bumps.