Bay seniors in search of some innocently romantic activity this Valentine’s Day might consider riding tandem through town, across the Golden Gate and returning via ferry boat from Sausalito. Watch for the blessed puddles now polka dotting the city after our recent New Testament level downpours. Bike and Roll in North Beach is just one of dozens of cycleries offering tandem bikes tho their fee has the discounted rate of $45 per day. Caution is strongly urged. Local motorists have been hitting cyclists with alarming regularity lately. And not all the two-wheeled angels seem that well acquainted with the concepts of red lights and stop signs.