pmgear doesn't report turn radius, but the sidecut is 125-99-114. 184 foils are 124-87-115 with radius of 20.4. So the soft 179's would be a guess around 25 with the stiffs being about 27, but those are total guesses. They're fairly straight, the 188's don't like to turn on groomers unless your really ontop of them, have to load the tips. The 179's turn better as expected, but they're simply not a groomer ski, they do it well but definetly not their strong point.