uh, i'm not sure what you mean. i think you'll probably want a flip flop hub though if i'm understanding your question. a fixed gear doesn't let you freewheel, that means you can't coast. flip flop hubs are set up to allow you to ride fixed on one side and then flip the wheel over if you wanna ride singlespeed.

i'm not sure if i answered your question, but last time i rode a tricycle the pedals were on the front wheel, so coasting was impossible. i guess the first bike i ever rode was fixed technically.