the breastplate's nipples

This worked slightly better than the previous brake when it was first fitted, mostly due to not flexing perceptibly when squeezed tight. I had been assuming that some of the poor performance was caused by the short travel which was possibly slightly the fault of the brake lever for not having a return spring and possibly also slightly blameable on the rear section of outer, which rubs against the rack stay and needs to be replaced, but also obviously partly due to the return spring of the brake not working particularly well, presumably due to shiteness. I now have an eyeletted seatpost clamp to fit to solve the outer-rubbing-on-rack-stay problem but will still have to replace the cable and outer and therefore took the brake off to give it a thorough cleaning to see how much difference it made. Not until I got to the very back did any baby-wiping make a difference but it's almost like a new brake, though probably not for very long if it's so susceptible to the ingress of sticky road-gunk, despite being designed for bikes which are designed to not be able to fit mudguards beneath the brakes of. There's also a little stupidity of design around the way that the back of the central bolt protrudes into the path of one of the arms when the central bolt is just slack enough to stop the whole thing being too tight to recoil which can possibly be solved by replacing a washer with a thin layer of grease the next time I can be bothered to take it all apart again.