Problem with Friction compensation

Unity Engine
1

Good Evening,

I want a ball to roll and bounce in an arena with a constant speed. So that the ball is rolling, I adjusted a little friction. Unfortunately, the ball loses its speed. How can I compensate for that?

Thank You.

Regards Heinz

2

Cheaty method:
In code
Rigidbody rb = GetComponent()
Rb.velocity = Rb.velocity.normalized * yourwantedamount