Selectorized vs. Spinlock: which type is better?

Selectorized dumbbells (like Bowflex style with a dial or pin) change weight in seconds and feel more like traditional dumbbells. Spinlock dumbbells use a threaded bar with weight plates that you manually load. They are cheaper and more durable, but changing weight takes 30 to 60 seconds. For circuit training or supersets where speed matters, selectorized wins. For straight sets where you rest between exercises, spinlock works fine and saves money.