Answer:
Because the bike is slowing down at a faster rate than you are.
Step-by-step explanation:
An object in motion will stay in motion. The bike is slowing down faster than the passenger. The bike will slow the rider down because the rider is hanging on but you will feel the force when the bike is breaking.
Newton's first law of motion - sometimes referred to as the law of inertia. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.