Thinking about a new helmet (Shark Evo-One) but it doesn't have D-ring -- uses the micro-metric buckle instead. So my question for anyone who has such a buckle, how do you attach helmet easily to the bike? Assuming the helmet lock on bike will be of no use. I do have one of those Aussie made HelmetLoks but it does not appear large enough to attach to seat rail or MP3 rack. Any ideas? Thanks!