Until we saw people gathered at Market and Duboce yesterday, hooting at passing cyclists and waving tire pumps. Was a rally mocking Obama, or mocking McCain mocking Obama? Neither -- it was the San Francisco Bicycle Coalition, offering patch kits and non-partisan air pressure to passing cyclists.

Speaking of politics, Democratic presidential candidates are more likely to be depicted riding a bike, but President Bush is also known to be an avid cyclist. Senator McCain has not been seen riding a bicycle, but he might decide to vote on one.

As for the tire-pressure-recommender himself, Senator Obama: his cycling has been the cause of much comment (seat adjusted correctly? helmet problematically evoking Michael Dukakis?). Our analysis of the photos sadly indicates under-inflated tires. We'd like to see at least 75 p.s.i. in those babies, Senator. We hear Washington is a high-pressure town. [Insert hot air joke here.]

Will the Bike Coalition pump up your tires again in the near future? No, but you can pump up the volume with the Urban Costume Karaoke Bicycle Brigade on Saturday, Aug. 9th at 4pm in Dolores Park. No candidate has yet dared to sing Madonna songs while biking around San Francisco in 80s costume.

Photo by alwaysupndown (used by permission). More on Flickr.