Installing a bigger tyre than the standard 140/60-17 size on the Gixxer 150 is not a feasible option. The 150/60 tyre is the largest size that can be installed on the bike. This is because the standard frame, suspension, and brakes are not designed to handle the extra weight of a larger tyre. Therefore, it is recommended to stick with the standard tyre size if you want to ensure the best performance and safety of your bike.