SFPD, Google Hosting Class on How to Improperly Lock Up Your Bike

Let us be totally clear here: this post isn't intended to rag on either organization for bicycle locking ignorance.  One organization is a government service tasked with crime prevention and security, the other parses vast amounts of information to provide us with the best resources available on any given subject, so it makes total sense that they'd be blanketing San Francisco with posters incorrectly telling people how to properly lock their bicycles.  I mean, neither is a bike company, so how would they know?

Therefore, in the interest in preventing anyone who may have seen this from being duped into this subpar locking strategy, we'd like to remind everyone how to actually lock their bike (via Sheldon Brown):

People tend to buy the big clunky U-locks because they don't know how to use them properly. A U-lock should go around the rear rim and tire, somewhere inside the rear triangle of the frame. There is no need to loop it around the seat tube as well, because the wheel cannot be pulled through the rear triangle.

Some will object that felons might cut the rear rim and tire to remove the lock. Believe me, this just doesn't happen in the real world. It is indeed possible to cut the rim with a hacksaw, working from the outside to the inside, but first, the tire must be removed or cut through. It would be a lot of work to steal a frame without a usable rear wheel, the most expensive part of a bike, after the frame.

The main reason SFPD/Google's suggested strategy doesn't work is the same reason cable locks just plain don't secure bikes: every thief has a pair of cutters that make quick work of the cable. If you use their locking suggestion, not only are you carrying around a relatively useless, bulky cable, you're likely to find both your wheels stolen, as opposed to just your front wheel.

Google it if you don't believe me.

Update: Matt Friedman of SFPD tells us the SF Bike Coalition is behind the poster and locking recommendation. Yikes.

Comments (13)

While we do believe you, we have seen on several occasions over 12 yrs that bike thief’s will indeed cut thru the back rim with hacksaw or some other device. I dont lock my bike up,but if i did its just better to get rid of quick release and get locking kind. ALWAYS u lock ur frame. Way easier to get new wheel set then new frame in most cases.(Unless ur bike is like the one in the picture)

Full disclosure: I work for Google, but not on anything related to this. Yes, I’ve seen the poster and have rolled my eyes at the diagram.

I find it amusing that you skip over the other sponsors who should also know better about how to lock up a bike, e.g. Bicycle Coalition, Valencia Cyclery. “I mean, neither is a bike company, so how would they know?” Yes, but there are two organizations also displayed jsut as prominently on that poster that are bike companies or coalitions who should know.

As an odee sckool bike mechanic I have great respect for Sheldon Brown. I don’t think this is quite right though. With quick release hubs I always remove the front wheel and lock it to the seat tube, the rear wheel, and the bike rack. This assumes a normal size U lock. That kind of U lock is vulnerable to a lever or jack attack. We would therefore add plumbing fittings to it for added strength. I now think the best way is to have two small size U locks, one for the front and one for the back. The front one goes around the down tube and the wheel, the rear one can be done in the Brown manner. I also think there are some high grade chains and locks that look pretty promising but they require a different method altogether.

Rumor has it that thieves along Market have taken to cutting the frame tubes of bikes locked this way. And yes, cutting through a rim is extremely difficult.

This post is pretty insufferable. That is a fine way to lock a bike , and less cumbersome then the rear triangle, while also protecting the front wheel.

I’m surprised no one has mentioned the pinhead wheel locks http://www.pinheadcomponents.com/ They’re great, and you don’t need to carry around extra cables/locks for the wheels. A set of these plus a small Ulock for the frame and you’re set. (I don’t work for the company, or anything like that).

However, nothing beats the tried and true strategy of simply not leaving your bike outside. Of course, that’s not always an option.

All of this debate makes me wish I were inside the event listening instead of valeting the bikes for the event. But when you do come, make sure to say hi to your human bike locks watching over your rides! :-)

if you have a few hundred dollars to replace the nuts and bolts, there’s this:


This is terrible advice. If the lock only goes through the rim and the bike is yanked on or bumped into, the rim can be easily bent.