Best Bowling Balls For Hook 2021Battle of the Urethanes – Back to the Future: (Rubicon UC3 – Motiv Purple Tank – Purple Hammer) December 5, 2021 - by - 3 Comments. This is going to happen people! I'm going to compare the Roto Grip Rubicon UC3, Motiv Purple Tank, and Hammer Purple Hammer bowling balls. WHat's the best urethane ball??