20x1.75" Black brushed sides single wall rims Loose ball, mid flange hub Flip-flop hub allows two different gear ratios with one wheel. Upgrade your BMX ride with this Diamondback 48H 20-inch rear wheel. The wheel offers such features as black brushed sides, single-wall rims, 48 14-gram black spokes, and a loose-ball mid-flange hub. Plus, the flip-flop design allows you to use two different gear ratios with the same hub. The wheel measures 20 inches in diameter by 1.75 inches wide.