Urban cycling is a good way to entertain and exercise. It enables you a new aspect to appreciate the city. However, as well as driving, urban cycling also has its own rules, which every cyclist should obey. Let’s figure out what those rules are.
The safety gear —
Helmet is a must.If you think they look dorky, then find a helmet that you like and will want to wear. You may have read articles saying that it's safer without, but wear it if only to protect yourself from the unexpected. Like getting stuck in MUNI tracks.
For night-time riding, have a bright front-facing blinking light, and a bright red light for your backpack or on the seat post of your bike. Notice I say "bright", which sounds redundant — but not all bike lights are equal. I know some people who even have three bike lights. Better to be seen than sorry.
Keeping your bike safe: U-lock and a cable. A U-lock on its own is great, but don't be surprised if you come back with a missing wheel. Use the cable to lock the other wheel. The cable is also super handy when you find yourself having to secure your bike to something that isn't a traditional bike rack. (Some tips on locking your bike: San Francisco Bicycle Coalition) IMPORTANT: it might look cool as shit to tuck your U-lock in your belt when you ride, but don't do it. Put it in your backpack, pannier, strap it to your bike rack, anything. The difference is falling and getting away with just a scrape and bruise, or falling and fracturing your hip or tailbone.
Some additional safety tips that aren't covered in the SF Bike Coalition's handy Rules of the Road Guide
Wherever possible, ride in a bike lane and choose bike routes per the Bike Coalition map. Legally, you are entitled to the full lane when there is no dedicated bike lane, although many drivers don't know this / pretend to not know.
If you're unsure about turning left on a busy street, err on the side of caution. Pull over at a crosswalk, and walk your bike over with pedestrians. It's not worth risking it if you're feeling unsure.
When crossing MUNI tracks, cross at an angle, and not parallel to the tracks. Getting stuck in the tracks is not uncommon, but can be avoided.
Be mindful of turns. Cars are legally allowed to enter the bike line in the last 200 feet before turning right (San Francisco Bicycle Coalition). If you see that happening, go to the left of them or simply slow down and ride behind them. There have been too many incidents of riders caught between a truck or a car on a right turn and then getting mowed down in the process.
Observe and learn to predict car behavior.Cars often turn without signaling, but you can usually tell when they start to slow down and inch across. Don't try to cut them off or beat them. Just get around them. You can yell at them if you want, but they can't hear you and don't care.
Etiquette wise — be courteous for your fellow bicyclists by being predictable to those who are sharing the streets with you. Dick behavior is everywhere on the road, but try not to be one yourself.
If it's another cyclist's right of way, yield to him/her. Especially at intersections, even if it means you have to slow down. This is not the Tour De France.
When passing another cyclist, give a simple heads up. I've have had many close calls where cyclists pass me without letting me know. All you need is to ring your bell or give a friendly "on your left/right!" so that they know to anticipate you and let you pass. I had cyclist swerve right into me because I didn't tell her I was passing. Lesson learned.
Yield to pedestrians! Don't run red lights! Cars go much, much faster. People on foot walk much, much slower. Whatever your stance is on the Idaho stop and however you decide to navigate stop signs— don't put other people's lives and your own at risk.
Queuing vs. cutting to the front at a light. I don't think people have strong feelings about this. I queue just because my bike is old and heavy and takes more pedal power to get going. If you're in a hurry AND you know that you can gun it fast, then by all means cut to the front. Some people don't like it and will give you stink-eye for it.
And don't ride on the sidewalk. It's illegal and it's just annoying to pedestrians trying to dodge you. If you're an adult, you're old enough to ride on the road.