Sirrus X is your ticket to riding more, and to places you never imagined possible. It's a comfortable, capable, "let's do stuff" kind of bike that will inspire you to ride more than you ever have before. With bigger, confidence inspiring tires, a slightly more upright riding position, a super intuitive one - by drivetrain, and plenty of mounts for racks and fenders - it's more than just a solid partner on pavement. Sirrus X is a dialed option when it's time to hit some gravel. Specialized have also equipped every Sirrus X with next - level comfort from our scientifically tested and ergonomically engineered Shared Platform Body Geometry saddle, handgrips, and pedals. Here's to your new life on two wheels. Choosing the bike size depends on the type of bike, your height, your riding style, and your preference. A correct fitting bike will be more comfortable, more efficient and more fun to ride. This bike size guide gives our customers general advice on choosing the right size. It is a guide only and we always recommend visiting one of our stores or contacting one of our experts.