Gear 101: What Is A CT Test, And How Does It Differ From A COR Test?
- Details
- Category: Inside Golf
- Published: 2020-04-29
By ANDREW TURSKY, Golf.com
In 2020, CT (characteristic time) tests on drivers are discussed more than ever due to increased testing on the PGA Tour. In this edition of Gear 101, we wanted to explain what CT testing actually is, and how it relates to the previous COR (coefficient of restitution) tests you’ve likely heard about in the past.
As you may remember in 2019 ahead of The Open Championship, Xander Schauffele had a run-in with the R&A after his driver failed a CT test. During the aftermath of that ordeal, the PGA Tour implemented mandatory driver testing for the 2019-2020 season. Ahead of the 2019 Safeway Open, five PGA Tour players reportedly failed the CT test conducted by the USGA Equipment Standards staff. Drivers continue to be CT tested at each event, and of course, all retail drivers are thoroughly tested before they hit shelves.
Prior to 2004, the R&A and the USGA tested drivers using a COR test, which tests for the spring-like effect of a club head. To measure COR of a golf club, tests were conducted by firing a golf ball from an air cannon at a club head and measuring the velocity at which the ball bounced off of different areas on the face. It’s a measure of energy transfer, so the lowest reading would be 0.000, where all energy was lost at impact, and 1.000 would be the highest, where all energy was transferred.