Serge Serfaty wrote:
That's my problem. I can get all these different numbers
but they are not the ones that I need for the Cambridge.
I can get SeeYou polars too.

The Discus or Discus 2 come with 2 different fuselages:
A and B.

You may wish to give some consider that any polar coefficient numbers
you obtain are, at best, simply an approximate curve fit to numbers
measured off of one particular clean glider on one particular day, that
flight computers use these approximate numbers to calculate a further
approximation for speed to fly, and that the real world difference in
performance between an A and B model Discus is quite likely smaller than
errors inherent in these approximations. Use some middle of the road B
polar numbers, the result will be close enough to reality of the day to
day performance of your ship...

Marc