There might be the following reasons why a variable speed bike was too heavy to ride: 1. Insufficient tire pressure: If the tire pressure is insufficient, it will increase the resistance when riding, making the car heavier. You can use the air pressure gauge to check the tire pressure. If it is insufficient, you can pump it to the appropriate pressure. 2. The chain is too tight or too loose: the chain is too tight or too loose will increase the resistance when riding, making the car heavier. You can use the chain stretcher to adjust the tightness of the chain to maintain the appropriate tension. 3. Failure of the brake system: If the brake system fails, the friction between the brake pads and the brake disc will increase, making the car heavier. You can check whether the brake system is normal. If you find a fault, you should repair or replace it in time. 4. The frame is deformed: If the frame is deformed, it will affect the structural stability and riding comfort of the car, making the car heavier. You can check if the frame is deformed. If it is deformed, it should be repaired or replaced in time. 5. [Too much weight: If you carry too many items while riding, it will increase the weight of the car and make the car heavier.] It could reduce the number of items to carry when riding and reduce the weight of the car. 6. Wheel Bearing Wear: If the wheel bearing is worn, it will affect the flexibility of the wheel rotation and make the car heavier. You can check whether the wheel bearings are worn. If they are found to be worn, they should be replaced in time. The above are some of the possible reasons why the variable speed bike is too heavy to ride. If you can't solve it yourself, it is recommended to seek the help of professional maintenance personnel. While waiting for the TV series, he could also click on the link below to read the classic original work of " The Legend of Mortal Cultivation "!