Originally Posted by
oneclick
Unfortunately they have nothing to keep the two ears of the blade apart, so with use and time[1] those move inwards, sometimes completely off the bushings.
So then they rattle and wobble.
This can be fixed - take them all apart and bend the ears outwards to suit.
[1] I've had some wobbly ones where the amount of use and time appears to have been zero.
I don't think they migrate in from time or use, I think it's always gotta be a whack of some kind, like bike fell over. Something exceeded its yield strength. That could happen on a brand new bike before the first round the block test ride, if you're unlucky. But the likelihood of seeing a whack like that definitely goes up over time.