Metal-on-metal; it is steel on aluminium (hence the sound). However, the important thing is to actually remember the break ratio front-to-back… 0% front-break, maybe 50% back and then there is this sound:
Ring my beeee-lllll, ring my bell…
There’s no bell or reflectors, fenders, lights or any other safety equipment mounted. No racks, baskets or other; the bike is stripped down to the bare bone and she is faster than most. Who? The Princess, Yu, obviously. Built for speed.
The squeaking from the non-existing front-brake pads is my bell…
Please see: Princess.