Originally Posted by
randyjawa
You will need the missing piece. If not replaced, there is nothing to properly hold the spring in place. It looks like the present set-up used a nut to achieve the same purpose but I would need to see where the brake mounts to make a better call. If it was working, so be it, but brakes are pretty important on a bicycle. You should try to get it right. Chances are you will be able to find another, if you look around.
Actually they had the spring tightened against the fork crown on the front, and a nut between the spring and the seat stay bridge on the rear. All of the nuts are the wrong threads and everything. It's a mess!