Rim Inner Width for Road

What are the advantages of narrow/wide rims and their respective tires?

Tires with different widths and profiles are used depending on the surface. The choice of tire width for the respective purpose in road cycling results in a recommendation for the rim inner width. Due to the positive influence of wider tires on handling and rolling performance, today’s tires are considerably wider than a few years ago. The choice of tire width determines the choice of the rim inner width (see Tire Pressure and Dimension). The tire width is also limited by the dimensions of the bike frame.

WIDE RIMS AND TIRES

Because wide tires require sufficient space between the wheel and the bike frame, it is only possible to fit wide rims with disc brake systems. The optimal combination of tire and rim inner width allows riding wide tires at a lower tire pressure as the rim provides greater support for the tire.

Field of application:

• Ideal for Endurance and Gran Fondo bikes due to greater comfort over long distances
• Ideal for off-road gravel riding with wide tires (particularly size 650b)

Advantages

•   Reduced rolling resistance due to greater contact area of the tire.
•   Greater stability and control due to greater contact area.
•   Greater comfort due to wide tires. These can be ridden at a lower tire pressure thanks to the greater support they provide, allowing them to absorb uneven elements in the surface.
•   Improved traction when cornering.

Disadvantages

• Greater weight and reduced acceleration due to additional rim and tire material.
• Not every frame is suitable for wide rims/tires. It is worth asking the bike manufacturer the maximum tire width suitable for the frame.

NARROW RIMS AND TIRES

Thanks to the narrow brake mount, narrow rims and tires are compatible with both disc and rim brakes. It is possible to use a tire width of up to approx. 25 mm.

Field of application:
• Aero wheels (with rim brakes)
• Road racing with rim or disc brakes

Advantages

•   Aerodynamic advantage due to reduced frontal surface with direct incident flow.
•   Direct, precise response due to greater tire pressure.
•   Can be used on conventional bike frames with rim brakes.

Disadvantages

•   Unstable handling due to reduced contact surface.
•   Increased rolling resistance due to the narrow, elongated oval contact surface and the increased stress on the hub, as highly inflated tires cannot absorb uneven elements on roads.
•   Reduced comfort which can lead to increased fatigue.
•   Reduced cornering traction.