There's a sticky about that exact subject: http://www.badmintoncentral.com/forums/showthread.php/54129-Why-2lbs-On-The-Cross Personally I do mains and crosses at the same tension (Pro's Pro Shuttle Express) and they come out looking the same as unstrung to me. Maybe I'll experiment the next time I restring a racket I've previously done and measure the difference. I only string up to 23-24lb though - it might be more relevant/necessary at higher tensions.
