Size 110/90-16 tires

Regardless of tire manufacturer, you must RAISE THE FRONT FENDER if you are installing a 110/90-16 front tire. You don't want bad things to happen.

110/90-16 GT501

110/90-16 BT45

This is especially applicable to Dunlop GT501 tires, as Dunlop doesn't sell size 100/90-16 in the US. Other manufacturers generally have the smaller size available, and you should go with the 100/90-16 in that case.

If you want to run a GT501 in the rear but don't want to raise the front fender, the GT501 rear/Metzeler Lasertec 100/90-16 front combination is popular.