Rear OEM Brake Pads Toast After 13,000KM

Sounds about normal,milage for everyone will vary, so your dont feel bad, i picked my r3t up second hand, it had 8k miles on it and rear brake was close to metal.
I changed mine in less than 5 mins there stupidly quick and easy to change. just buy new ceramic pads and go easy on your rear breaking. or not, cheap enough without the stealship install
 
FWIW i am pretty hard on the fronts and use the rear to stabilise rather than haul up...i just changed my OEM pads at 25k km
 
Just check that your not resting your foot on the pedal while riding and not noticing it, I was doing that when I first got my bike and hadn't got round to setting up the peddle height properly.

The type of pads also make a difference, I put scintered on the rear and std on the front.

I don't use the rear brake that often only in heavy braking and to change lines while cornering as the front brakes do most of the work. The bikes mass moves forward during braking putting more weight and traction on the front wheel giving better braking and grip as you increase the braking effect on the front, just physics.

Always surprises me when people seem to rely on their back brake, on my old crap with 7" or 8" single leading drums, the back brake is critical as part of the whole braking system (the old brakes are terrifying when you go back to them after modern brakes) but each to their own.

I replace my back brake pads much less often than the fronts.
 
You may have had some slight sticking with the pads....happened to my wife's car after only 20 km on the rear. Now I pull all the pads off all my vehicles once per year....buff the wear points with a wire brush and no more issues.
 
I ride a lot in traffic due to my commute and I'm always filtering (lane splitting) and because of that I found on both my Thunderbird I had before, and the Rocket I have now that I have to change the rear pads every time I change the rear tyre (approx. 5k miles). For me it's just one of those things due to the type of riding I do most.
 
......what is this 'rear brake' you speak of.....?.....never heard of it....
 
I agree that 13K kms (8K miles) is VERY premature.
Perhaps this is an R3T thing, but I just changed out my front and rear OEMs at 32K miles and I seek out the twisties, ride hard and frequently trail brake.
Yours must be a bad pad(s), mechanical or rider habit issue.
I hope you soon sort it all out!
Please let us all know when you do.
 

Could be bad pads as I posted recently I went through a set of rear pads in less than 2000k I replaced them with a set of Brembo pads 4000ks ago, still like new same riding conditions just "soft " pads