Comfort issue is one of the major concerns regarding backpack design. Previous studies have tried to improve backpack comfort in different ways such as reducing load weights and balancing the load distribution. However, few studies have investigated the issues related to thermal comfort, which is a fundamental problem for bicycle rider with backpacks. This study aimed at improving the user’s experience for those who cycle with backpacks by providing a better ventilation design and body support. Interviews were firstly completed among fifty participants to investigate their usage pattern and usability issues regarding backpack use. Following, a test was conducted with participants to find out the possible difficulties and problems when cycling with a backpack. The main sweating areas on the back were identified. Design criteria were formulated, and a product prototype was developed accordingly. An experiment was then conducted to evaluate the effectiveness of the ventilation design in two conditions of walking and cycling. Skin temperatures of the back were measured using the infrared thermographic camera. Results showed that the shell support of the backpack design could provide better air circulation in the gap between the body and the backpack. Wearing the ventilating backpack could significantly decrease back temperature and improve the user’s thermal comfort while cycling.