Le mardi 16 janvier 2018 11:17:54 UTC+1, Surge a écritÂ*:

The Cirrus may have been rated for loops when it was new and free of repairs, control slop, etc. so unless your 40+ year old glider is in pristine condition with no accident history you will need to take all those approved maneuvers and Vne with a pinch of salt.
I would not try it myself.

A loop means entry speed of about 100 kts and pulling 3-3.5 g.
If you don't think you can do that with a certain glider, that glider is probably not airworthy in the first place.