This bicycle flywheel is only compatible with models that already have a gear system. If your bike is not equipped with a gear system (e.g., models like BK2, BK5, BK8S, BK35), this flywheel is not suitable and cannot be retrofitted. Please make sure your electric bicycle supports a gear system before purchasing.

Important Notes:

• This flywheel is designed exclusively for bikes with a gear system.
• Models without a gear system (such as BK2, BK5, BK8S, BK35) cannot be modified to install this flywheel. Please do not purchase if your bike does not have a gear system.
• This accessory may be shipped directly from China, with an estimated delivery time of 10-15 days.

Please select the correct flywheel based on your electric bicycle model and requirements. For any questions or assistance, please contact our customer service team at [email protected].