I bought the 2008 rush hour (the blue one) in early september, so its still fairy new. I've been riding fixed without brakes, but I don't ride that much. maybe 40 miles a week if the weathers nice. Since owning this bike my lock ring has come loose 4 times. Usually at inopportune times. Slips when i pedal backwards forwards, track stand, everything... Since I'm under warranty, and get free tune ups on the bike, I've had them tighten it (i don't have a lock wring wrench). The guys at the bike shop are a bit useless sometimes, So I don't know if its them or if theres any problems with the hub. My friends who is a bike mechanic is convinced its fine and wants to borrow a wrench from his shop and really wail on it. Long story short has anyone had similar problems with the same bike or just in general and a good way to solve this. Ppl have mentioned locktite but other people I've spoken to say its a terrible idea.