I Sprocketing usually refers to a modification wherein you replace one or both sprockets with a different size one. Switching to a smaller rear (or a bigger front) makes the overall gearing higher and vice versa. A higher geared bike will usually cruise at a lower rpm for any given speed and may also increase fuel economy. On the other hand, lower gearing ( a bigger rear or a smaller front sprocket) is good for stunting or for added punch in each gear, though at the cost of the speed possible in each gear.