I've owned lots of different kinds of bike stands over the years and this is the worst ever.I've got a couple of bikes stored on these, and they're stored together in a corner of a garage where I keep my bike tools, accessories, pump, etc. Seems like I can't grab either one of my bikes or any other biking gear without knocking one of my bikes over. I realize that it would stay upright if I didn't hit it. But a bike standing in a rack ought to be able to withstand a gentle nudge without falling over.I've examined these several times to make sure I've assembled them correctly - I think it's just a faulty design. The wheels help get the whole thing rolling, and once they slide just a bit after tapping the bike, the bike is history.Maybe the folks who like these racks are just less clumsy than I am. Well - that's almost certainly true. But still, these are too prone to allowing my bikes to fall.Soon headed for the dumpster...