CHINA has halved the number of stolen bicycles to about 2 million in the past nine months, police said on Thursday. The drop follows a campaign to clamp down on bicycle theft. China, home to a world record 460 million bicycles, has also cracked thousands of bike theft gangs, police officials said during a news conference Web-cast on China.com.cn. The government recently introduced a system of identification numbers for bicycles. Buyers must register their bikes in their real names.