What is the diameter of 700c wheels?
2 Answers
700*21C refers to a 700C size tire with a width of 21mm. 700C indicates a wheel with a rim size of 622mm. The earliest 700C wheels used 35C tires, resulting in a total wheel diameter of approximately 700mm when including the tire. The 'C' stands for millimeters. When replacing rims, pay attention to the following parameters: 1. Center Bore (CB): This refers to the size of the center hole of the rim. Although rims with different center bore sizes can be installed using adapters, it is not recommended for safety reasons. 2. Pitch Circle Diameter (PCD): For example, a rim with a PCD of 5x120mm means it has 5 lug bolts arranged in a circle with a diameter of 120mm. This value should also adhere to the original specifications.
As a cycling enthusiast, I often get asked about the 700c wheel size. In fact, 700c is the most common wheel size for road bikes, with a fixed rim diameter of 622mm - a precise number that's easier to just memorize. When you add the tire, the total wheel diameter typically ranges between 700-710mm depending mainly on tire thickness, usually labeled as 28 or 29 inches. From my long-distance riding experience, this size performs exceptionally well on paved roads, offering both speed and stability. When replacing tires, you must choose models compatible with 622mm rims, otherwise they won't fit properly and could compromise safety. Many tires marked as 700×c in the market correspond to this size, with width options like 32c or 28c - just select based on road conditions and comfort preference. Don't get too hung up on the terminology; you'll grasp it easily after a few practical attempts.
