Tester: Eric McKeegan/Oona McKeegan Kids today. Back when I was knee-high to a grasshopper, kids’ bikes had 20 inch wheels, steel frames and no gears. Also, no helmets. But things change, and in this case, for the better. This is a full-fledged, 24 inch-wheeled, adventure-ready fat bike for kids and short-statured adults, not a bike-shaped-object ...