1. Check the frame number: Every giant bicycle has a unique frame number, which can be found on the body. If the frame number is maliciously destroyed or modified, or the frame number cannot be found, it may be a fake car.

2. Query QR code: scan the QR code on the frame, and you can enter the QR code to query the authenticity.

3. Check the body logo: Real giant bicycles generally have a three-dimensional logo, and the text below the logo should be clearly visible. In addition, real giant bicycles will be painted on the signs, while fake bicycles may be pasted on them.

4. Check the details of the car body: Real giant bicycles usually have exquisite manufacturing details, such as the steel seal and bar code on the five-way and the bar code on the front fork. If these details are flawed or do not meet the specifications, then it may be a fake car.

5. Smell inspection: If the vehicle has a pungent smell, it may have been refurbished in banana oil. This smell usually lasts for several weeks, so if the vehicle doesn't have this smell, it may be a fake car.

The above are some ways to test the authenticity of giant bicycles, but the most accurate way is to choose regular channels and authorized dealers when buying, so as to ensure that you can buy real giant bicycles.