Hmm, not so good.
My K13 has the panniers fitted etc. However been used to a top box for commuting the last 2 years.
Anywa brings my question:
What is the K1300S like through traffic with panniers on full time? Looks the same width as mirrors but any info would be great. Dont want to fit if going to hold me up and will adjust rack to fit top box if required again??
The panniers are less width than the mirrors, even expanded (mirrors = cats' whiskers!).
But note that the panniers are lower down than the mirrors, and cars/road furniture can be wider lower to the ground.
I went for a nice gap between a car and a temporary roadworks sign thinking 'Ah, neat', and then clipped the (low) road sign with the pannier. At least I didn't hit the car. Just a scuff on the pannier, so not a huge problem - just a surprise.
In summary, they're smaller than you imagine. Most of the time.