The ruckus triple tree is wider than the met triple tree. Therefore the stock met fender doesn’t fit over the ruckus tree without modification.
Option 1 is to trim the sides of the original fender, although the rear panel may also have to be removed to fit the wheel dependent on wheel and shocks.
Photo courtesy of Tre Watkins:
Photo Courtesy of Jonathan Breigh
Photo courtesy of unknown:
The fender can apparently be heated to fit over (there is approx 1/2” different on width between the two trees).
The alternative is to fit a later 2013-2017 met fender. This requires modification and a new bracket also.
Photos courtesy of Aaron Ford (he used to sell brackets):
Photos courtesy of Derek Marciniok:
Photos courtesy of Oslo Zoomer Garage:
Photos courtesy of Tommy Chan:
And a final one from Jay Braxton as to how to wire up the indicators: