Bicycle

Bicycle provide a form of transportation for a majority of Chinese, so there are cycling side roads set aside on all major roads. It seems that Beijing is the flattest city in the world, this allows for very easy bike riding. It might look scary but riding a bicycle is a great way to see Beijing, as you can pretty much go anywhere and don't have to worry about car traffic-- just bike traffic. It is recommend that a new visitor to Beijing watch how the locals ride their bikes before they attempt a try; although don't necessarily copy their riding style! It also recommends that one be careful with parking--sometimes random parking may resulting a fine.
Bicycle Rental
There are many places that rent bikes--large repair shops as well as hotels--with with prices ranging from 2 yuan per hour to 40 yuan per day depending on the style of bike. Perhaps the largest rental office is Master Wang which is located accross from of SCITECH Plaza.
Purchasing a Bicycle
The most popular Chinese brands are: Flying Pigeon (Feige), Phoenix (Fenghuang) and Forever (Yongjiu). You should be able to purchase a reliable Chinese bicyle for about 50 USD.
Bicycle Repair
You can try a large repair shop but there are abundant repair stalls with all the spare parts. A new inner tube should cost lest than 15 yuan, and an inner tube and tire about 30 yuan--all including labor.