Can I change rotor size with disc brakes? I have a new bike with 160mm rotors and Avid BB5 brakes. I wanted to step up to Avid BB7 brakes as they seem easier to adjust. The BB7s come packaged with rotor options -- 160 / 180 / 200 mm.


Can I go up a rotor size? 
What would limit this? My fork has a brand but the manufacturer's website has no indication of rotor size limitation.
Is there any advantage to going up?


I should mention that this is for an electric-assist bike with 20" wheels.  I do drag a trailer and live in a hilly area, so good/better brake performance going downhills is definitely appreciated.
Rotor size is determined by the brake mount adapter.
So everything else ie. the caliper - stays the same. Only the Adapter changes.

You must check your fork manufacturer for the maximum size of rotor the fork can be safely operated with.

Also check frame clearances (at the rear) for enough clearance for the size of rotor you are selecting.

Going up rotor sizes is specifically for more braking power.