RockyMount's Brass Knuckles rack gets your bike from point A to point B with the minimum of hassle and the maximum of security. The aluminum arm uses finely indexed ratcheting to hold front bike wheels from 20- to 29-inches with widths from skinny road tires to fat DH monsters. Form-fitting mounting hardware plays nicely with almost any roof-mounted bars: round, square, or aero. When your bike isn't on the roof, the arm folds down for an extremely low profile for minimal wind noise and maximum gas mileage. For extra security, you can lock the bike to the rack and the rack to your car with lock cores (sold separately).