The bike wheels sit in fold down trays and there is a bracket that simply comes down on the top of the frame of each bike securing them tightly. You hate having a blanket covering your feet and you can not do that when you have company over. At its worst the leaking is similar to a semi open back or open back headphone. The other pair I had purchased was a similar height heel (1/4? lower), but the heel was wider, making it easier to walk in and more comfortable. FYI (does not impact review)This dock will only support 1 mediocre monitor with a Macbook. I really liked these when I first got them, they were very comfortable and supportive. Sturdy and easy to install. I do wish you didn?t have to take them off to charge. I have had them a week and thought I would provide a quick review. My 2yr old loves her pink crocs