get these:
http://stores.sportbiketrackgear.com...l.bok?no=10050
i have the previous version, as do many others. they are not bulky (will fit under a pair of jeans no problem).
the new version seems to be a significant improvement over the current model. i almost can't wait till my old ones wear out so i can get the new ones
more discussion on various knee/shin armor:
http://www.ninjette.org/forums/showthread.php?t=58451