|The knobbier the better
The first step is to use a pair of knobby tires - the bigger the knobs the better. Using a drill, you'll want to screw 5/8"sheet metal screws into the inside of the tire. With a bit of luck, you'll end up placing the screw right into the center of one of the knobs. 50 screws per tire will do the job.
|With self-tapping screws, drilling is easy
Alternate the knobs that you put the screws into otherwise you'll find that your tire will go bump,bump,bump as you ride. The ends of the screws are very sharp so handle the tires carefully. Through riding on pavement, the screws will eventually wear down to a smaller size and lose some of their sharpness. Don't worry - that wearing down won't affect their performance.
|You can also use 1/2" screws