(Yicai) Oct. 9 -- Shares of JAC Motors hit the daily limit down again today after a video showing brake pedal brackets breaking during tests of the Maextro V800, a luxury vehicle it jointly developed with Huawei Technologies, sparked safety concerns.

JAC Motors [SHA: 600418] hit the daily 10 percent decline limit for the second consecutive session before recovering to close 8 percent lower at CNY22.75 (USD3.40) per share.

The Hefei-based automaker jointly developed premium new energy vehicle brand Maextro with telecoms equipment giant Huawei under the latter's Harmony Intelligent Mobility Alliance. The Maextro V800, a large extended-range electric multi-purpose vehicle launched in August, targets the premium business market and is priced between CNY766,000 and CNY1 million (USD114,290 to USD151,590).

Automotive information platform Dongchedi, owned by ByteDance, recently released a video showing the brake pedal brackets of three Maextro V800 vehicles fracturing during tests measuring braking performance from 100 kilometers per hour to a complete stop, resulting in a loss of braking ability.

Responding to the video yesterday, Maextro said its braking systems had been developed and validated to standards exceeding national and industry requirements, and that no brake pedal bracket base fractures had occurred during actual use since deliveries began.

“User safety is always our top priority," Maextro said. "Even in non-standard extreme testing conditions, we still hope to provide users with higher security redundancy: we will further optimize the design of this component and provide free upgrade options for users.”

The company added that it would systematically review and strengthen the design validation, testing parameters, and production quality management of the relevant components.

Brake Testing Methods Under Scrutiny

Dongchedi disputed Maextro's characterization of the tests as extreme. A representative of the platform said braking tests from 100 kilometers per hour to a complete stop are among the most basic vehicle performance assessments, the National Business Daily reported.

Dongchedi said this was the first time it had encountered a brake pedal bracket fracture during such testing, with similar fractures occurring at the same location in three consecutive tests.

Addressing questions about the force applied to the brake pedal during the tests, Dongchedi said the actual peak force was 1,612 newtons, equivalent to the weight of about 164 kilograms and substantially more than drivers typically apply during routine braking.

The dispute has also raised questions about how much force a brake pedal should withstand. No unified industry standard specifies the maximum force a driver can apply to a brake pedal, according to Qiu Jincao, deputy secretary-general of the Automotive Advanced Power Systems Branch of the China Society of Automotive Engineers.

“Under normal driver operation, the brake pedal should not break, regardless of the circumstances,” Qiu said. He added that automakers establish their own internal standards based on vehicle structures and safety redundancy requirements.

Other experts noted that the direction of force applied to the brake pedal, testing methods, and ultimate load data could all affect the results. The precise cause of the fractures has yet to be determined and requires further verification.

As of publication, Yicai found that the video was no longer available for viewing on several platforms, including Bilibili, WeChat Channels, RedNote and Douyin.

Editor: Emmi Laine