why do the fastest bicycles have really thin tyres but the fastest cars have very wide tyres

Question

why do the fastest bicycles have really thin tyres but the fastest cars have very wide tyres

In: Engineering

Answer 1

This is actually changing as road bikes move towards wider tires.

There are a number of factors to balance including:

1. Air resistance.

2. Rolling friction and contact patch size.

3. The feel of the bike and riding comfort.

Many of those issues don’t matter to the same extent with cars. For instance aerodynamics… When the car itself is 6 feet wide it matters a lot less just how thick the tires are. Similarly riding comfort is less important when the human isn’t being asked to provide the power. This more naturally biases those cars towards wider lower pressure tires, but these days road bikes moving in the same direction.