Although I have changed the brakes of my previous bike, it all went wrong this time...
Un-screwing the old V brake link fixing bolt, also brought out the mounting boss ( btw is this common? Since these bosses are not welded to the frame, how can one make sure that they won't come off with the fixing bolt?).
To make the long story short after taking the assembly to a bike shop, they 'fixed' it. Which was not the case as they deflected the boss.
So while trying to fit the new V-Brakes it all went terribly wrong and now one of the stopper pins is deflected (as can be seen in the photo).
Can this be fixed? Is there a spare part just for the stopper pin ring? Or should I consider buying a new V-Brake?
If it's a Shimano brake, even a part as small as that may be available as a special order spare. Otherwise, as long as the pin is able to engage the retaining holes all is still good.
And no, the v-brake boss coming out isn't common. Usually, the bigger thread of the boss vs the brake arm screw is enough to ensure that the assembly comes apart at the "right" place. A bit of threadlock should be sufficient to keep it from happening.