From the Mailbag:Dear Sam:Can bikes legally be chained to traffic posts or light poles?Gene, via e-mailDear Gene:Bike riders, especially in Williamsburg, have had their bikes seized by the NYPD after chaining their bikes to signposts and light posts. As former Mayor Ed Koch would say, "This is REE-DICULOUS!"There is a section of the Administrative Code (16-122) that Brooklyn North cops have been relying on to issue these summonses. But this section was meant to deal with abandoned cars and bikes left for, say, seven days or more (the length of time a car is allowed to remain parked in the same spot).According to Noah Budnick of Transportation Alternatives, NYPD's East Village precinct cops have got it right. They tag bikes that look abandoned and, if after a week or so the bikes haven't been moved, they are removed. Gridlock Sam is asking the NYPD to "cease and desist" from seizing bikes except after tagging and waiting a full seven days. After all, Gridlock Sam chains his bike to street poles all the time.Gridlock Sam