Tires and sizes

Road bike tires and sizes

You will often see road bike tires labeled something like 700×25. The first number, in this case 700, indicates the diameter of the tire in millimeters and is standard in the category. The second number, 25, shows the width of the actual rubber tire in millimeters and is more likely to vary across individual bikes in the category.

  • 25mm: This tire width offers the smoothest ride, most comfort, stability and speed for road tires. This tire size is great for any road rider looking for a more compliant ride and for those racers who want to gain comfort and speed.
  • 23mm: This tire width is being seen less and less on road bikes today. These tires still offer a degree of stability but are also lightweight and more aerodynamic than the wider range of tire sizes. These wheels are great for cyclists who want to increase their speed, who are training, or competing.

Mountain bike tires and sizes

  • 26”: These wheels provide good maneuverability and stability while riding but lack in rolling over larger obstacles and rolling fast on flatter sections of trail.
  • 27.5”: 27.5-inch tires and wheels are the newest size to be introduced to mountain biking, they combine the handling and maneuvering confidence of 26” wheels with the rollover ability of larger wheel sizes.
  • 29”: 29-inch or 29er wheels and tires are the fastest rolling of all the wheel sizes. Most commonly used for cross country mountain bike racing, these wheels can roll over moderately large obstacles quite easily and roll the fastest on flat sections of trail or road.

Tubes vs. tubeless

Most bikes run rubber tubes inside of the tires to allow the bike to roll without damaging the rims. However, many riders are converting their bikes over to a tubeless setup. The rims are taped with a special tubeless tape to prevent leaks and tubeless ready tires are put onto the rims. Then the tires are filled with tubeless sealant that will seal holes and leaks and allows the rider to remove their tubes from the tires, saving weight and removing the possibility of getting a flat tire.

See more bike anatomy