theory - Truck/Bike Rule

Since women rarely travel by way of truck or bicycle, it is very attention-grabbing to see them driving either. Because of this, it magnifies the attractiveness, or unattractiveness, of the woman traveling by bike/truck.

A decent looking woman would get J'approved while riding a truck because she is not a hillbilly.

A large woman riding a bike would look like she is about to crush the bike or plow through a brick wall.

It's science.