The Royal Enfield Classic 350 comes with a larger front wheel compared to the rear wheel for a specific reason. The larger front wheel, typically 19 inches in diameter, is intended to enhance stability and improve handling characteristics of the motorcycle.
A larger front wheel provides better stability during straight-line riding and helps absorb bumps and uneven road surfaces more effectively. It also offers increased gyroscopic effect, which aids in maintaining balance and reducing steering effort.
Changing the front wheel to a smaller 18-inch wheel may alter the motorcycle's handling dynamics and stability. It could affect the overall balance and may compromise the intended design and performance of the Classic 350. It is generally recommended to stick with the manufacturer's specifications for wheels and tires unless you have expert knowledge and experience in modifying motorcycles.
If you are considering any modifications, it is advisable to consult with a professional mechanic or an authorized Royal Enfield service center to understand the potential impacts on the motorcycle's performance, handling, and safety. They can provide guidance based on their expertise and ensure any modifications are done properly and in line with your preferences and requirements.