Smoothing capacitor for scooter regulator - High constant current drawn
A smoothing cap is loaded only when the rectifier voltage output is higher than the capacitor voltage. This gives you current spikes at the top of the rectified sine, and no current at all for the other times.

You are right the rectifier needs to be able to handle the current spikes, or it will burn out.

A better design used another single diode, and put a substantially smaller smooothing cap behind it, just big enough for powering the headlight.

BTW: A 45W LED headlight is much brighter than other people's normal headlights, and most likely, than allowed. The scooter has no license and you will run into insurance problems if you are involved into an accident.