Thanks for the replies guys. Experienced Python pilots have advised me that the CG may be further forward than called out by the manual i.e., 63mm from the bottom wing leading edge as opposed to the recommended 85mm which is on the spar of the bottom wing. Come to think of it isn't the spar of a bipe's bottom wing a pretty far aft CG? It is in my experience (Balsa USA 33% Flybaby bipe and Miles Reed 27% Week Solution). Most bipes, if I pick up the plane from the rear center of the top wing and she's a little nose heavy I give it a try.