The Rubicon features the etrax s20 solid coverstock and the new mild asymmetric Rondure core. Etrax is a cleaner and more responsive formula like R2S, but stronger overall. The new Rondure core in 15 pounds has a 2.49 RG, .052 differential, and an .011 split, or intermediate differential. The rg and diff are exactly the same as the Idols, and there’s somewhat of a shape difference, but especially when comparing it to the Idol Pro, which shares the same base cover formula, you can see extra traction and extra aggression down lane out of the Rubicon. It’s very reminiscent of balls like the Code X and Alpha Crux, which were higher traction balls with a firm and predictable motion down lane, but still with a focus on control. With 1 being the lowest and 10 being the highest, my hook rating is 8, my length rating is 5, and my backend strength rating is 6.