Just bought a brand new "Windsor" comfort bike from BD.Assembled it and can't get the rear brake to work right.The cable seems to loosen after squeezing levers caused because the calipers don't have enough snap to tension the cable upon release of the lever.The type is a " C-star Alloy silver V brake Linear Pull."Anybody have a clue to how to fix it?The fronts work perfectly.Yes I know they're cheap and the bike is cheap but they should work nonetheless.I bought 7 of these bikes in different sizes in order to start a NYC bicycle tour business.I will be gone all day so if you need more details I'll respond tonight.Thanks.