A good, easy-to-ride bike for a senior is one that’s comfortable for long hours in the saddle. A bike with a slightly longer wheelbase will help keep the rider from feeling twitchy. A bike with a slightly longer wheelbase will help keep the rider from feeling twitchy. Moreover, the best bike for seniors is a step-through frame. This kind of bike has a frame that is horizontal to the ground and has pedals at the bottom and a seat at the top. The step-through frame makes it easy for seniors to put their feet on the ground while they're sitting on their bikes.