I assemble trikes upside down. One day I was trying to get one done fast for a birthday of a handicapped child and installed the 3 speed hub right side up. Pedaled backwards. Shop got a frantic call. Went out to fix it at the birthday party and fixed it. Parents were understanding. Kid thought it was a hoot. Glad they were gracious.
other great was forgetting the washer for the crank bolt.
Howard Darr
Clymer PA USA