1958 Harley-Davidson Duo-Glide The 1952 K Model was the first big Harley-Davidson with rear suspension. For 1958 the FL and EL big twins got sprung rear suspension and became Duo-Glides, boldly noted on the front fender. This first year Duo-Glide is especially stylish in red and white with white grips and saddlebags plus whitewall tires. Continuing to give serious touring riders what they wanted, the optional King of the Highway package offered saddlebags, dual exhaust, fender tips, bumpers and