Eventually you will reach a wide chasm that is tough to cross or you will get sick of missing the top big coin or a magnet and learn how to jump. You need to build up speed before a jump by pulling off a trick or sliding on ice. If you are too slow, the best timed jumps won't help you. Once you have some speed you need to time your jumps so that you leave the ramp before the end. It's about finding the sweet spot in the middle of the ramp where you need to launch from. Remember that you don't charge up for a jump, as soon as you tap, you jump. spend a few runs just practicing getting the most air on every jump you can. After fifteen minutes you'll know when to tap, and when to wait.