Here’s how to bike without breaking a sweat. Hop on an electric one at Aquatic Park. It does all the work unless you switch to the pedal option. Then head off on a tour that takes you west along the waterfront, over the Golden Gate and down to Sausalito where you’ll ride a ferry back to the City. It takes 3-4 hours, bikes go up to 35 mph and cost $60 on the Electric Bike Tours Site, but the last time the Geezer looked it was $34.75 on goldstar.com.