Errant parkers beware. Clowns on bicycles will patrol bike lanes tomorrow and slap a parking ticket cars blocking bicyclists' paths. Times Up!, a bicycle advocacy group, is sending out the clowns to help keep bike paths safe. Says clown Barbara Ross: "I just want to make the conditions better and better so riders and families get out there and ride." The environmental group will also host a short theatrical production where someone dressed as Assembly Speaker Sheldon Silver will refuse a $500 million dollar check. (The act is supposed to mock Silver's refusal to head to Albany so his chamber can vote on the mayor's congestion pricing plan that would net the cash.)