You mean LH (Lufthansa)?
You will have 20 kg per person in europe. If CX can check your luggage thru to the final destination (they should but not sure if they are willing to) then yoiu are safe.
If you need to pick up and recheck you should have no more than 22 kg check in luggage per person - otherwise it gets expensive quick. You can find the fees on the lufthansa website.