I just bought a new, improved version of On Guard's Pitbull Mini. My 5 year old NYC Kryptonite was starting to jam. The Pitbull mini seems solid and the key lock portion seems improved. I have a GT Hybrid but I can't lock my frame and rear wheel to the rack. Has anyone heard or read anything new concerning whether or not the "Sheldon Brown" locking method works? I guess I should state that I will be locking up on the mean streets of Chicago which has a very high rate of bike thefts.