1. Each fastened screw and nut of the bicycle should be tightened and not loose or fall off.
2. All rotating parts should operate flexibly, and there should be no jamming or staleness. For example, the front and rear wheels should rotate flexibly, and they should not swing left and right and jump up and down. The wheels should be able to swing back and forth briskly when they are about to stop, and they should not stop turning suddenly. The handlebars should be flexibly turned left and right, the pedal shaft and the crank should be fastened, not loose between each other, and the turning should be flexible.
3. The gear shift of the transmission car is correct within the shift range, the shift position should be clear, and there must be no neutral gear in the middle.
4. The chain should be tight and suitable for flexible operation. Repeatedly shake the crank sprocket forward and backward by hand, the chain runs flexibly, and there should be no chain skipping or falling off.
5. Hold the front and rear parts of the saddle with both hands, press the front end of the saddle with one hand, and the front end of the saddle must not collapse. Turn the saddle horizontally with both hands, and the saddle should not rotate.
6. Selection of brakes and brake system: Hold the handlebar with both hands, brake left and right while pushing and pulling the bicycle forward and backward. At this time, the wheels should not rotate; loosen the handle, and the brake system should be able to reset quickly.
7. The surface of all parts and components should be clean, free from stains and rust. The trademark decals should be complete and clear, without sharp edge burrs, etc., such as the edge of the mud board and chain cover should not have the feeling of being tied, and the end of the brake and the steel rope should be protected. Sets and so on.
8. Observe the brand or label of the parts. Generally speaking, good parts are marked with obvious trademark marks and the patterns are clear and exquisite, while inferior parts are rarely marked or rough.
9. The switch action of each part is sensitive and reliable.
10. Speed regulation is stable and reliable. Slowly turn the speed control handle, the motor should start and accelerate smoothly. After releasing the handle, the handle can be quickly reset and the motor decelerates evenly.
11. The brakes are powered off quickly and reliably. Turn the speed control handle, after the motor is running, the motor can be powered off immediately after the brake is applied. If there is a power display, you can see that the display returns to zero.
12. The battery is easy to disassemble and assemble. The weight of a lead-acid battery is generally about 13.5kg. Because it needs to be disassembled and assembled every day, the location of the battery must be suitable for your body.