Roto Grip Gremlin Bowling Ball Review

The Gremlin rolls into the HP3 line for Roto Grip just in time for the fall 2025 season. This ball features the new Rondure MaxD asymmetrical weight block. It has a few slight differences from the Rondure core that was used in the Rubicon series of bowling balls. The RG of the Rondure MaxD core is slightly higher (2.50″) compared to the 2.49″ value from the original. The differential gets bumped up from 0.052″ in the Rondure to 0.058″ in the Rondure MaxD, while the intermediate differential drops slightly from 0.011″ to 0.010″. The coverstock was changed multiple times in the various Rubicon releases, with the Rubicon UC2 being the pearlized version. That ball featured eTrax Pearl, while the Gremlin uses the new V-R1 Pearl Reactive coverstock. These changes keep the Gremlin from being a straight remake of the Rubicon UC2, instead making it an improvement on it. The new coverstock comes out of the box with Power Edge, giving the ball a shiny finish. These elements helped the Gremlin to offer a little more length, a bigger move off the breakpoint, and more back end recovery compared to the Rubicon UC2. This is the first Roto Grip ball we’ve reviewed in a while that doesn’t use the Amplified Inertia (AI) outer core system.

Cranker

Cranker liked the Gremlin just a little more than the other two bowlers on the fresh medium oil pattern. This ball allowed him to play where he is most comfortable, starting left and sending it right. The ball cleared the front of the lane very easily, retaining energy for the breakpoint and back end. He saw a similar motion to one of his favorite balls, the Rubicon UC2. The Gremlin was a little cleaner, offered a little more shape off the spot, and provided a little