WHEEL SIZE
for Road Bikes

Why are there different wheel sizes in road racing?

The 700c (622 mm / 29 inches) is the most common wheel size for road racing. The 650b (584 mm / 27.5 inches) wheel size is used in specific areas. Each wheel size offers unique advantages for different kinds of riding.

 

650b WHEEL SIZE

Field of application:
•    Ideal for racing on unpaved roads (gravel)
•    Ideal for smaller bike frames with adapted geometries

 

Advantages

•    Ideal for wide, high-volume tires if there is enough space between wheel/fork and wheel/chain stay (large clearance).
•    Option of lower tire pressure, which results in greater traction when cornering, accelerating and braking, improved rolling resistance on rough roads and trails as well as greater comfort.
•    Also suitable for small bicycle frames where the frame dictates wheel size.

 

Disadvantages

•    The combination of a small wheel size and a wide tire leads to reduced acceleration and reduced response.
•    Less rollover performance and rolling resistance with the same tire and tire pressure compared to 700c.
•    Limited choice of road tires due to the rather rare wheel size.
 

 

WHEEL SIZE 700c

Field of application:
•    Ideal for racing on asphalt roads
•    Ideal for competition racing on unpaved roads (gravel)

 

Advantages

•    Wide choice of tires as it is considered the standardized wheel diameter for asphalt roads.
•    Smoother ride due to the larger wheel diameter.
•    Reduced inertia when the wheel is in motion.

 

Disadvantages

•    Slightly reduced acceleration due to inertia compared to the same rim built.
•    Slightly greater weight due to longer spokes and additional rim material.