Hammer Purple Pearl Urethane 78D Bowling Ball Review

The Hammer Purple Pearl Urethane 78D is approved for most USBC competitions, outside of a few select events. This ball features the Urethane Pearl 78D coverstock that was used previously on Hammer’s Black Pearl Urethane in April 2025, but the cores are different in these two bowling balls. The Black Pearl Urethane used the LED weight block, with an RG of 2.650″ and a differential of 0.015″. The Purple Pearl Urethane 78D uses the Super LED design, which features a slightly lower RG of 2.632″ and a significantly higher differential of 0.034″. This resulted in nearly double the observed track flare on the Purple Pearl Urethane 78D compared to the Black Pearl Urethane. Both balls come out of the box at a 500 SiaAir finish, with the Black Pearl Urethane providing more length and less total hook than the Purple Pearl Urethane 78D. We needed a lot of friction on the lane surface to see the right shape from the Purple Pearl Urethane 78D, and we weren’t afraid to add more surface to help improve the reaction.

Cranker

Cranker liked the added flare and downlane motion he saw from the Purple Pearl Urethane 78D on the dry oil pattern. He could start the ball farther left compared to where he played this pattern with the Black Pearl Urethane. The ball picked up earlier and had a bit more motion off the end of the pattern. Cranker is the only one of our bowlers who owns a Purple Pearl Urethane (the purple pin version), and he was able to use it to compare to this new version. Both balls were drilled with the same layouts, and both balls were at their box finishes. Even with the duller surface and the stronger core shape, the 78D urethane shell provided much less traction and