I work in a city where we make a lot of narcotic arrests off of bicycle violations. Here are a few pointers I have picked up in my experience and from other officers:
1. Watch the handle bars. Many subjects are placing needles or small knives underneath tape, within the holes on the side of the handle bars or underneath the rubber grips.
2. Check underneath the seats, after the subject is detained safely. Many subjects hide small bags of narcotics, stems (usually glass or metal cylinder tubes used for smoking crack), and other small weapons there.
3. As always watch the subject’s eye movements, hands, and see if the subject is keeping his back to you. In our city many of the subjects that ride bicycles with a firearm have it in the back waistband or back pocket.
4. Check if the bicycle has spokes. If so, do they move easily? I usually check this by pushing the toe of my boot in a circle. Some subjects are removing the spokes and sharpening them for weapons. If they have done this, usually the sharpened spoke will be able to be removed with minimal force.
5. Is the subject wearing a hat or have a cell phone? Check the inside of the hat, underneath the small flap of material surrounding the inside edge. Once again narcotics and stems are found here. Does the cell phone work? If not, check where the battery should be. Small bags of narcotics are sometimes hidden in place of a cell phone battery.