Yamaha list it as a 51/43 but it will pull the same rpm and same mph on testing as a 48/42 with no other clutch changes, back to back testing,so that's really what the ramp angles will work out to be. I have not measured one on a cmm but the day I tested it was accurate as I checked many helix, they all will change rpm and mph with as little as 2 degree change. The manufacture of helix also makes a difference as the ramp radius is different from helix brand to helix brand. some are more aggressive then others even with the same angles (example 50/40 bender to a 50/40 Dalton).
