My second instructable but my first shot with k'nex please comment.
Step 1: Make the rear axle
This step uses one gray k'nex rod two white k'nex conectors and four stops.
Step 2: Make the front clip
This step uses two Red k'nex rods, two purple connectors, a blue rod, wheel and tire, big gear, two blue spacers, brown drive thingy
Step 3: Make the seat
This step uses thirteen green connectors, five white rods, two blue rods, two red connectors, and a yellow rod
Step 4: Connect The K'nex
Snap the Green and white connections to the front clip then put the piece you made second in step three through the holes in the green k'nex and put on clips. Then clip on the rear axle to the front clip YOU ARE DONE. This trike could easily have a motor but i didn't have one.