Two dumbbells, 30 weight settings. NordicTrack takes a swing at the adjustable weight market with a design aimed at improving ease of use. Sure, we might remember our moms watching daytime TV while swishing imaginary ski tracks. But the brand that helped start the craze for low-impact workouts now has its eyes on the weight rack. NordicTrack last summer launched the Select-A-Weight system. The two-dumbbell set does the work of 15 different pairs of dumbbells, with weights ranging from 10 to 50 pounds on each.  In short: Adjustable dumbbells aren’t new, but NordicTrack offers standard features and a lower price than some of the competition. These dumbbells provide a great at-home weight set for beginners and intermediate lifters. It won’t replace a gym membership for advanced fitness buffs, but the Select-A-Weight system proved an easy-to-use compromise between high-end and budget alternatives. To understand what these dumbbells are and what they do well, it helps to know what’s already out there. Adjustable dumbbells have been around in some form for decades. Primitive iterations worked like any barbell, where users slid on a plate, followed by a locking collar to hold it in pla...