Originally Posted by DougZ73
Do you know for a fact that the R has weaker brakes?? As far as I understood, the X just runs a bigger rotor, therefore, it(caliper) is mounted further out on the fork tube, achievable with an adapter bracket. I had always thought the calipers and pads were the same, albeit with different first three digits in the part number, due to Yamaha's numbering system, and those first three digits referencing the bike the parts are for.
physics would say bigger rotor = more stopping power given everything else being equal