At my 600 mile service my friendly local BMW shop informed me that my rear rotor was blue, the pads were shot, and both the rotors and pads needed to be replaced. Front was fine. A nice $700 addition to my first service. My bike is 2017.5 Rallye. I have never had this happen before in 30 years of riding. My previous GS (2014) didn't eat brakes or rotors. Riding style, boots, and brake lever are same on both bikes. I don't ride the rear brake or even cover it. I'm wondering if slow speed riding splitting lanes on a trip could have heated the rotor if I was feathering the front brake. Perhaps light use of the front triggered the linked rear? Seems this is a possibility reading through posts. Would my Nav Data Log be of any help? Dealer says the wheel spins fine by the way (engine off).