My Grandfather was nice enough to give me his late 60's early 70's american flyer in original condition. I put on new wheels, tires, handle bars, wide crank, and a 66cc skyhawk custom paint (by me). 44t sprocket and 24" (20"wheels) topped out at 31.4mph. 40t and 36t sprockets on the way, along with a new Brooks saddle and laid back seat post by Pirate Cyles.