The recommended tire pressure can vary depending on factors such as the type of tire, load, and riding conditions. However, the general recommended tire pressure for a Royal Enfield Classic 350 is around 25 psi for the front tire and 32 psi for the rear tire.
Inflating the front tire to 30 psi and the rear tire to 40 psi might be slightly higher than the recommended values. Higher tire pressure can result in a harsher ride, reduced traction, and increased wear in the center of the tire tread. It's generally advisable to follow the manufacturer's recommendations for tire pressure to ensure optimal performance, handling, and safety.
To be certain about the correct tire pressure for your specific motorcycle model, I recommend referring to the owner's manual or contacting a Royal Enfield authorized service center. They can provide you with accurate information and guidelines based on your motorcycle's specifications.