My MTB alternates between front brake right, rear left or rear right if I'm only running one brake.
BMX (for me) is always right lever for the rear whether iot has one or two brakes.
Fixed, when I used a front brake, was always right hand.
Pay attention to the fact you're using the bike on the road though. When turning right you may have to signal so it would be more useful if the lever was on the left hand side so you can still brake if necessary.
General rule of thumb is what ever feels right.
My MTB alternates between front brake right, rear left or rear right if I'm only running one brake.
BMX (for me) is always right lever for the rear whether iot has one or two brakes.
Fixed, when I used a front brake, was always right hand.
Pay attention to the fact you're using the bike on the road though. When turning right you may have to signal so it would be more useful if the lever was on the left hand side so you can still brake if necessary.