Final answer:
The diameter of the bike wheel in millimeters is 660.4 millimeters.
Step-by-step explanation:
To convert the diameter of the bike wheel from inches to millimeters, we will use the conversion factor of 25.4 millimeters per inch. Given that the bike wheel's diameter is 26 inches, we can calculate the diameter in millimeters by multiplying 26 by 25.4. Therefore, the bike wheel's diameter in millimeters is 660.4 millimeters.