Chrome Steel 20" by 1.75" 36 Spoke Wheel Set. Front and Rear Coaster Wheel. 12g UCP 3/8 Axle 20" wheels measure 16 in diameter (that is from end to end). 20 in Rear Wheel Coaster Foot Brake (meaning when you pedal backwards the wheel will brake). Wheel comes with rear sprocket and mounting hardware. Fits tires from 20x1.75 to 20x2.125. We have tires and tubes for this wheel, which are sold separately. Chrome Steel 20" by 1.75" Wheel Set. Front and Rear Coaster Wheel.