Contrarian bicyclists protest Bush and take arrests: Thousands of cyclists rode through the streets of Manhattan last night in an anti-Republican, pro-environment display of bike power that ended in more than 100 arrests by the police after the ride blocked some streets. Despite tension over police warnings to obey traffic laws against blocking traffic and running red lights, the cyclists - numbering 5,000, the police say - did just that in a meandering course that started at Union Square and wound its way to the West Side, Central Park, Midtown and the East Village. As of 11 p.m., Paul J. Browne, a police spokesman, said that officers were still processing people who were detained, but that he expected more than 100 people to face charges, mainly for disorderly conduct. The arrests, two days before the convention starts, seemed to herald a busy period for the police, who must patrol a stream of demonstrations large and small, several each day. The police on Thursday made 22-convention related arrests, more than three times the number during the entire Democratic National Convention in Boston.