If you are in to Beijing, and want to satisfy a bicycle hankering, you must head to Beixinqiao. Bicycle heaven. Take the 5 subway line to the Yongehong stop (Lama Temple). Visit the temple which is one of Beijing's great landmarks, and then go to the nearby Natooke fixie shop, if that is your desire
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If not, walk back to the main street, Yongehong Nan Da Jie and then head south.
At Jiaodouku Lu, cross the street. Now you are approaching bicycle heaven. If you go west, you will run into a strip of local shops and a Giant bicycle super store.


I'll say this for the Taiwanese Giant brand, they know how to do a bicycle shop up right! The have a huge stock of proprietary bikes, nicely displayed with upscale components including Shimano and Campy conveniently located nearby. From the looks of things, I'd say that the French "Randonneur" style of bike is coming back into vogue.
On the north side of Jiaodouku Lu is a Giant eCycle super-store, if you'd rather let the volts due the pedalling.

If you head back to the corner of Jiaodouku Lu and Yonghehong lu and head south, you'll see are the Pawnshops, one on either side of the road, followed by some more local shops. The road is now called Dong Si Shi Tiao

The pawnshops usually have a good selection of roadsters: British, Japanese and Chinese, of course.
South of that on Dong Si Shi Tiao are several local shops sell new roadsters: Flying Pigeon, Phoenix, Forever. There's a lot of folding bikes and eCycles mixed, in there of course.

There are also several street side bike doctors in the area.

At the extreme south on the map is a shop selling high end German and Chinese bikes, particularly the Merida brand. If you feel like a carbon fiber race bike, you can find them here.
I would then turn around and head north again to the junction of Jiaodouku. Then turn east. You are now in a section of the street is called "Gui Jie", or Ghost Street. It is wall-to-wall restaurants for about a kilometer and a half, many of which are open all night. The "ghosts" in this case are the diners who come in at 3 AM wearing pajamas for some late night hot pot. I've been at 1:30 AM and many restuarants still had a waiting line outside! At any time, this is a great place to get some good food and a Yanjing beer.
(Map credit to Google Maps)