You need to connect with local club and group rides and find some new routes. Potomac Pedalers Touring Club (bikepptc.org) has rides all over the region every weekend and many weekdays. Check local bikes shops for shop rides (there are several shops in G'town). If you care for off-road, the C&O Canal Towpath starts down in G'town and runs 184 miles west. You can cross Key Bridge and take the Custis and W&OD trails out to Loudon County VA and plenty of good biking there. bikewashington.org is a good local info website with some bike routes (I'd also check some of the online route sites) and there is an active BikeWashingtonDC email group on Yahoo groups. That should get you started. DC itself is going to be city riding; I live in the NoVA suburbs so I don't have any 1st-hand info beyond the C&O and Custis trails. Good luck!