I'm more familiar with leg suck on a trike where the frame is a few inches off the ground and it is easy to get your leg caught between the frame and the ground if your feet come off the pedals. I also ride a Linear LWB and an Haluzak Horizon SWB in addition to a trike and can't imagine even the possibility of getting my leg caught by anything, even the USS handlebars. Hitting my heel against the front wheel on a turn is a different matter but that soon becomes second nature to avoid with even a few miles under your belt.