My CM is build in 2010. Later models might have heavier springs.
Nominal 10 lb: Measured in CM 10.0 lb, free length 139-143 mm, outer diameter ø9.4-9.6 mm, 36 coils.
Nominal 11 lb: Measured in CM 12.3-13.1 lb, free length 126-130 mm, outer diameter ø8.9-9.3 mm, 30-31 coils.
Nominal 13 lb: Measured in CM 12.7-13.7 lb, free length 125-128 mm, outer diameter ø8.8-9.1 mm, 29-30 coils.
All springs have ø1.0 mm wire.