Bicycles (自行车 zìxíngchē) were once the most common form of transportation in China, but has declined as many people have upgraded to electric bikes and motorcycles. But in major cities, bikeshare programs remain common and popular.
There are two major dangers for cyclists in China:
Bicycle repair shops are frequent apparently anywhere in cities and rural areas; non-Chinese speaking tourists might find it a bit difficult, but you can just look for bikes and tires. For a quick fix to a sudden flat tire, there are also many people standing by along the road with a bowl of water and a repair kit ready. For special parts like disc brake, bring a spare if not using them in big cities.
The fairly new phenomenon of dockless rideshare bikes has dramatically reversed this decline, with both neat rows and messy piles now ubiquitous on the streets of China's larger cities — Shanghai alone has close to two million of them. These operate on a grab'n'go basis: you use your mobile phone to unlock any free bike, pay ¥1-2 per 30 minutes while using them, and drop them off pretty much anywhere you like. The largest operators Mobike (dead link: January 2023) (orange) have English apps. Dockless bikes are built to last, meaning they're heavy, clunky and ungeared, but for travellers, they can be a cheap, convenient means of transport that is better than trying to deal with public transport for hours on end. The Hangzhou Public Bicycle sharing system was the largest in the world in 2013, although it has since been overtaken by a number of dockless bike share operators such as Mobike. By 2015, it was expanded to over 84,000 bikes and 3,354 stations.
For something a little better, buying a bicycle is easy. Dahon, Merianda and Giant are three most popular quality brands and all cities have their distributors. Prices vary from as little as ¥150 to over ¥10,000. For a reasonably well-equipped mountain bike for riding to areas like Tibet, expect around ¥3,000-4,500 for a bike. Big cities like Shanghai and Beijing usually stock more upmarket bikes, but if you have very specific requirements, Hong Kong is still the last hope for buying them.
China is a vast country and it provides serious cyclists with challenges to bike across mountains and desert. If you are considering biking across Tibet, check whether there are restrictions or a requirement to obtain a permit and hire a tour guide.
See Karakoram Highway for one spectacular but difficult route. Companies such as Bike China and Intrepid Travel organize such tours for small groups.
If you plan to cycle through China, get a visa before your journey, as it can be hard to get one along the way. Avoid saying that the journey will be by bike, as embassy personnel may not like that, and Xinjiang and Tibet are politically sensitive. The visa is valid for any border crossing and transport method anyway (except Tibet).
If you want to take your bicycle to another part of the country, you can ship (托运) it by train as checked baggage. The fee to ship a bicycle-sized item is usually much less than the cost of a passenger ticket for the same distance. This can be done at most major stations; the baggage department is usually somewhere near the main station building. Checked baggage does not travel on the same train with you (in fact, you don't even need to be traveling by train); it may take a few days to get to your destination. There was no need to disassemble the bike in any way, or to deflate the tires, to send it on as baggage. The staff at the baggage compartment may use some tarp and scotch tape to partially cover some parts of the bicycle for a bit of protection when traveling, or you may do that yourself using your own packing material. For more details on using checked luggage service, see High-speed rail in China#Checked luggage and parcel service.
A foldable bicycle can be taken with you as carry-on luggage on most trains; however, you may be asked to put it into a bag, so make sure to have a big enough bag for a folded bicycle to fit in! With a typical hard bunk or soft bunk ticket, one can easily put a folded bike into one's compartment's luggage space (which is between the car's roof and the ceiling of the car's corridor, and is accessible from the compartment itself). On a high-speed rail line, some cars have convenient luggage space near the door, where a folded bike can easily fit; others don't, so storing the bike without inconveniencing oneself and fellow passengers may be somewhat problematic.
Regional and long-distance buses have luggage space under their floor. One can sometimes see people transporting items as large as a motorcycle, so if the bus is not very full, and does not carry too much passenger luggage already, it may sometimes be possible to put even a regular (not folding) bike there; one may need to negotiate with the driver.
There is, of course, no problem taking a bicycle on a ferry that's meant to accommodate both passengers and vehicles; but even a passenger-only ferry would often allow bicycles. Inquire at the terminal, or watch what other passengers are doing.