What weight were you flying at? Because i fly a 150 Cub, and glide approach at 50 knots is eminently possible to either a 3 point or a wheeler, solo and 60 litres (tug, half tanks or a bit less. Full is 135). Not a lot faster than you. Max weight i would use 55, both cases full flap, which on mine is 60 degrees. Most cubs have a bit less flap, mine was a crop duster and has some oddities. Short landing back of the drag curve and power five knots less. You might want to check the pitot static installation.