I called my local bearing supplier and got a quote of $9.75 each for double sealed. Is it worth it? I think so, my swing arm design depends that I get sealed bearings in the wheels so I can pass an axle bolt from one side to the other. Plus these are sealed bearings, son! Sealed! yo! no grease to smear on your brakes, nessesitating another cleaning. Another Plus, Big ASS axle. five eighths of and inch in diameter. I like big axles, they are harder to bend...Thats how I think.