Xtracycle EdgeRunner, 48 lb.
With its durable, stiff, and predictable-handling welded steel frame and 350-lb total capacity, the EdgeRunner is the brute of the bunch. Even fully loaded, the EdgeRunner is surprisingly manageable, thanks to a minuscule 20-inch rear wheel that lowers the center of gravity and extends the wheelbase for extra stability without making the bike longer from end to end.
The EdgeRunner's biggest advantage, however, is its modular "LT" cargo platform, which has a diverse catalog of bits that includes parcel shelves, baby seats, custom bags, and even a clever SideCar add-on to support another 250 pounds of gear on its generous 22- by 27-inch deck. Configure it all just right and you can safely haul three toddlers to school on your way to Whole Foods with a side trip to Home Depot for a new washing machine.
The build kit is impressively solid, too, especially coming from such a small company with a slick-shifting 3 by 9 drivetrain, front and rear Avid disc brakes, and superb Schwalbe tires. [$2,000; xtracycle.com]