The disc brake industry in 2011 was ready for a major push.

A representative from a certain bus manufacturer told our reporter that disc brakes—gradually adopted for buses and trucks in Europe starting in the 1970s—began to see widespread use from the 1990s onward. Today, nearly all buses in Europe are equipped with disc brakes as standard. But what about the situation with disc brakes in China? For buses longer than 9 meters, all wheels must be fitted with disc brakes. This is a requirement outlined in the draft revision of GB 7258, the "Technical Specifications for Operational Safety of Motor Vehicles," which was submitted for review in May 2010. If all goes smoothly, mandatory implementation could take effect as early as 2011.

Outperforms others significantly

Compared to drum brakes, the advantages of disc brakes have been widely recognized. Drum brakes suffer from poor braking stability, with significant variations in braking force depending on the road surface, making them harder to control. In contrast, disc brakes deliver strong braking power when assisted by hydraulic systems, offering superior comfort and consistent performance. They perform better than drum brakes across a variety of road conditions, especially on long downhill stretches where prolonged braking is required.

European brake system manufacturers, together with automotive companies, once conducted a comparative test of two types of brakes in a mountainous region. When vehicles were driven steadily downhill on a 11-kilometer-long mountain road with a vertical drop exceeding 1,000 meters and an average gradient close to 10%, disc brakes maintained the desired speed using a constant braking pressure of just 2.4 bar (1 bar = 100,000 pascals). In contrast, drum brakes required gradually increasing pressure—by the time the vehicles reached the bottom of the hill, the braking pressure had already climbed to 4.3 bar.

When vehicles brake on long downhill stretches, the brakes generate significant amounts of heat. If this heat isn’t effectively dissipated, it can severely compromise the vehicle’s braking performance. Many buses are prone to brake failure when descending long slopes, primarily due to thermal fade in drum brakes. In contrast, disc brakes allow air to flow directly through the brake discs, providing superior cooling and preventing thermal fade altogether—plus, they reduce the risk of tire blowouts. This was stated by Mr. Liu, Service Manager for Haiger Buses in Shandong.

Disc brakes also offer convenience in terms of service. Mr. Liu explained: Under normal conditions, the friction pads in drum brakes need to be replaced every 20,000 kilometers, whereas the friction pads in disc brakes typically last about 50,000 kilometers before requiring replacement.

Currently, medium- to high-end intercity coaches in China have widely adopted disc brakes. Li Dongmei, Chief Engineer at Youth Automobile Group Co., Ltd., explained: "Youth Automobile began using disc brakes on its buses several years ago, though standard configurations typically still feature front disc brakes paired with rear drum brakes."

There are obstacles, but it's essential and inevitable.

The obstacle to promoting disc brakes domestically stems from cost. Disc brakes have a more complex structure than drum brakes and also place higher demands on brake calipers and the hydraulic system, resulting in a higher manufacturing cost compared to drum brakes.

According to a journalist's investigation, the price of a single domestically produced disc brake is 800 to 1,000 yuan higher than that of drum brakes, and a complete front-axle set—including just the brakes—costs an additional 1,500 to 2,000 yuan.

Developed countries like Europe and the U.S. have essentially phased out drum brakes altogether, as their users are largely insensitive to price. In contrast, domestic companies place significant emphasis on vehicle pricing. Since disc brakes cost about twice as much as drum brakes, replacing all drum brakes with disc brakes—and adding other auxiliary components—would increase the cost of each vehicle by an additional 10,000 to 20,000 yuan. "That’s why widespread adoption remains challenging," Mr. Liu noted.

In fact, even with mandatory standards in place, promoting disc brakes remains quite challenging. Wu Xiaoguang believes that domestic disc brake technology still needs improvement, and there isn’t yet a well-established supply system for accessories. Moreover, the service and maintenance infrastructure is struggling to keep up with market demand. On top of this, users are still unfamiliar with disc brakes and haven’t fully mastered the proper operating techniques, leading to occasional instances of improper handling. Only after these foundational tasks are completed—and prices are brought down—can disc brakes truly gain wider adoption. However, this won’t happen overnight.

Lack of systematic technical research

Chen Xufeng, Chairman of Longzhong Holding Group, does not agree with the above issue: The poor reputation of domestically produced disc brakes was indeed an objective problem in the past two years, primarily because some products were launched too hastily without undergoing thorough verification before entering the market. However, after more than two years of continuous improvement and fine-tuning, the quality of many of these products has now met industry standards. From the perspective of the products themselves, locally manufactured disc brakes currently show little gap compared to their foreign counterparts.

Nevertheless, Chen Xufeng also acknowledged that the disc brake industry still faces certain challenges. China's development of bus disc brakes began in the early 2000s and has since achieved notable progress—but it still lacks systematic technological research. For instance, the issue of proper matching between disc brakes and air chambers has yet to gain significant attention within the industry. Domestically, few companies conduct comprehensive matching tests by integrating disc brakes directly with air chambers. If the air chamber sealing on the exterior of the disc brake is inadequate, it can lead to rusting, compromising the braking performance and shortening the service life of the brake assembly. Currently, while the price gap between foreign-made disc brakes and products from domestic manufacturers isn't substantial, there’s a considerable disparity in the cost of air chambers: imported air chambers paired with disc brakes are priced at least three times higher than domestically produced ones, adding up to more than 1,000 yuan extra.

The bus is the main force.

Although disc brakes are now being used in an increasing number of buses, there is still a significant gap compared to their widespread adoption levels abroad.

In Europe, passenger buses have largely adopted the front-disc, rear-drum braking configuration. Domestically, most buses still primarily use the front-disc, rear-drum setup. Haiger buses mainly rely on imported disc brakes, with ZF products accounting for a significant share. For domestically produced disc brakes, they’ve chosen products from Fangsheng in Liuzhou, Guangxi, while models shorter than 10 meters often feature components from Wuhan Yuanfeng. Mr. Liu told the reporter.

About half of Yutong Bus's models are equipped with disc brakes. Wu Xiaoguang, Deputy Chief Engineer at Zhengzhou Yutong Bus Co., Ltd., told reporters: "Among the models featuring disc brakes, a significant number are buses—particularly low-floor, low-entry buses, which all come standard with disc brakes on their chassis. However, if we exclude buses from the count, the actual number of vehicles opting for disc brakes isn't very high."

Domestic disc brakes still have shortcomings.

In addition to their excellent braking performance, disc brakes also effectively reduce noise. We began mass-producing disc brakes in 2006, and since 2007, all newly purchased vehicles have been equipped with disc brakes. Overall, domestic products seem slightly less reliable than their foreign counterparts, according to a relevant official from the Beijing Public Transportation Corporation.

Mr. Liu, the Shandong After-Sales Service Manager at Higer Bus, believes that although disc brakes offer numerous advantages, their relatively complex technology can actually lead to a higher failure rate when used in areas with challenging road conditions, causing inconvenience for users.

Disc brake failures are less common than drum brake failures.

Mr. Liu told the reporter: "Among the vehicles our company services, issues with disc brakes are mostly concentrated in domestic brands. The main reason is the inferior quality of materials—for instance, the friction material doesn’t yet meet the standards of foreign products. Additionally, domestically produced disc brakes still lag behind their international counterparts in terms of precision and intricate details; for example, the concentricity of Chinese-made disc brakes tends to be lower. These factors can all contribute to reduced stability in disc brake systems."

Optimistic about the 2011 market

In Chen Xufeng's view, the disc brake industry in 2011 was poised for a major push. After nearly a decade of development, the disc brake industry has become relatively mature, and the mandatory adoption of disc brakes will ensure strong market demand. I expect that this year alone, there will be a配套 market for at least 30,000 buses. Therefore, we have already made thorough preparations in terms of production capacity and resources. Other disc brake companies have also been gearing up—currently, the leading enterprises in the industry are producing more than 10,000 sets per month, easily meeting this year's market needs.