When it comes to bicycles, few topics create more confusion than wheel and tire sizes. You’ve probably seen terms like 700C, 650B, 29”, or 27.5” — but what do they actually mean? And more importantly, which size is right for your ride? In this week’s Questions Answered, we break down the history, the differences, and what you need to know to feel confident about your tires. A Little History Behind the Numbers The “700C” and “650B” designations come from a French system that described the overall diameter of the wheel and tire — not the actual wheel size. In that system, the “700” represented about 700 millimeters from edge to edge, while the letter (A, B, or C) described the tire’s width. Over time, those numbers stuck around, even as tire standards evolved. Today, the 700C wheel corresponds to a 622mm bead seat diameter, while 650B measures 584mm. The numbers may not match up perfectly anymore, but they continue to serve as helpful categories for sizing and performance. 700C: Speed and Efficiency The 700C wheel — commonly seen on road bikes, commuters, and many of our Priority models — is built for efficiency. Its larger diameter allows the bike to roll smoothly and cover more ground per pedal stroke. That means: Less rolling resistance on pavement and packed surfaces Higher top speed with less effort A more connected road feel ideal for fitness or daily commuting If you value a quick, responsive ride that feels light and fast, 700C wheels are the way to go. 650B: Comfort and Control The 650B (or 27.5”) wheel sits slightly smaller, which allows for wider tires and a more forgiving ride. With more air volume in the tire, you’ll feel less of the bumps and chatter on uneven terrain — perfect for riders who prioritize comfort or find themselves mixing pavement and gravel. Handles tight turns with ease Offers more traction and comfort on rougher roads Ideal for gravel, adventure, and all-road riding Choosing the Right Wheel Size for You So, which wheel is best? It depends on where and how you ride. Choose 700C if your rides are mostly on roads or bike paths, and you value speed and efficiency. Choose 650B if you like to explore rougher routes, want more cushioning, or prefer the stability of a wider tire. No matter which you choose, both sizes are backed by the same Priority design philosophy — low maintenance, high quality, and ready for the ride ahead. Confidence Through Understanding At Priority Bicycles, we believe an informed rider is a confident rider. Wheel and tire sizing may sound technical, but at the end of the day, it’s about matching your bike to your lifestyle. Whether you’re gliding through city streets or tackling weekend trails, the right tire size helps you ride smoother, safer, and with more enjoyment.