Tricycle is signed first like bicycle, then the ASL number 3 sign is added to signify the three wheels of a trike. First, it looks like you are pedaling a bicycle with your feet. Make both hands into fists, then make vertical circles in the air in front of your body. Finally, hold up the number '3' on your dominant hand by raising your thumb and index and middle fingers while the rest of the fingers are curled in, with the palm side facing you.
Tricycle can be used with any pedal-powered toy your child may use, including bicycles, and even push-powered toys. Mobility toys tend to be highly motivational signs for babies, so they make good early signs.
If your baby has siblings, or there are adult bike riders at home, your little one will be curious about biking. Consider purchasing a tricycle, if not a balancing bike, which can be used as early as age two.